File: /usr/src/linux/drivers/net/zlib.c
1 /*
2 * This file is derived from various .h and .c files from the zlib-1.0.4
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets. See zlib.h for conditions of
6 * distribution and use.
7 *
8 * Changes that have been made include:
9 * - added Z_PACKET_FLUSH (see zlib.h for details)
10 * - added inflateIncomp and deflateOutputPending
11 * - allow strm->next_out to be NULL, meaning discard the output
12 *
13 * $Id: zlib.c,v 1.3 1997/12/23 10:47:42 paulus Exp $
14 */
15
16 /*
17 * ==FILEVERSION 971210==
18 *
19 * This marker is used by the Linux installation script to determine
20 * whether an up-to-date version of this file is already installed.
21 */
22
23 #define NO_DUMMY_DECL
24 #define NO_ZCFUNCS
25 #define MY_ZCALLOC
26
27 #if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
28 #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */
29 #endif
30
31
32 /* +++ zutil.h */
33 /* zutil.h -- internal interface and configuration of the compression library
34 * Copyright (C) 1995-1996 Jean-loup Gailly.
35 * For conditions of distribution and use, see copyright notice in zlib.h
36 */
37
38 /* WARNING: this file should *not* be used by applications. It is
39 part of the implementation of the compression library and is
40 subject to change. Applications should only use zlib.h.
41 */
42
43 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
44
45 #ifndef _Z_UTIL_H
46 #define _Z_UTIL_H
47
48 #include "zlib.h"
49
50 #if defined(KERNEL) || defined(_KERNEL)
51 /* Assume this is a *BSD or SVR4 kernel */
52 #include <sys/types.h>
53 #include <sys/time.h>
54 #include <sys/systm.h>
55 # define HAVE_MEMCPY
56 # define memcpy(d, s, n) bcopy((s), (d), (n))
57 # define memset(d, v, n) bzero((d), (n))
58 # define memcmp bcmp
59
60 #else
61 #if defined(__KERNEL__)
62 /* Assume this is a Linux kernel */
63 #include <linux/string.h>
64 #define HAVE_MEMCPY
65
66 #else /* not kernel */
67
68 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
69 # include <stddef.h>
70 # include <errno.h>
71 #else
72 extern int errno;
73 #endif
74 #ifdef STDC
75 # include <string.h>
76 # include <stdlib.h>
77 #endif
78 #endif /* __KERNEL__ */
79 #endif /* _KERNEL || KERNEL */
80
81 #ifndef local
82 # define local static
83 #endif
84 /* compile with -Dlocal if your debugger can't find static symbols */
85
86 typedef unsigned char uch;
87 typedef uch FAR uchf;
88 typedef unsigned short ush;
89 typedef ush FAR ushf;
90 typedef unsigned long ulg;
91
92 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
93 /* (size given to avoid silly warnings with Visual C++) */
94
95 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
96
97 #define ERR_RETURN(strm,err) \
98 return (strm->msg = (char*)ERR_MSG(err), (err))
99 /* To be used only when the state is known to be valid */
100
101 /* common constants */
102
103 #ifndef DEF_WBITS
104 # define DEF_WBITS MAX_WBITS
105 #endif
106 /* default windowBits for decompression. MAX_WBITS is for compression only */
107
108 #if MAX_MEM_LEVEL >= 8
109 # define DEF_MEM_LEVEL 8
110 #else
111 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
112 #endif
113 /* default memLevel */
114
115 #define STORED_BLOCK 0
116 #define STATIC_TREES 1
117 #define DYN_TREES 2
118 /* The three kinds of block type */
119
120 #define MIN_MATCH 3
121 #define MAX_MATCH 258
122 /* The minimum and maximum match lengths */
123
124 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
125
126 /* target dependencies */
127
128 #ifdef MSDOS
129 # define OS_CODE 0x00
130 # ifdef __TURBOC__
131 # include <alloc.h>
132 # else /* MSC or DJGPP */
133 # include <malloc.h>
134 # endif
135 #endif
136
137 #ifdef OS2
138 # define OS_CODE 0x06
139 #endif
140
141 #ifdef WIN32 /* Window 95 & Windows NT */
142 # define OS_CODE 0x0b
143 #endif
144
145 #if defined(VAXC) || defined(VMS)
146 # define OS_CODE 0x02
147 # define FOPEN(name, mode) \
148 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
149 #endif
150
151 #ifdef AMIGA
152 # define OS_CODE 0x01
153 #endif
154
155 #if defined(ATARI) || defined(atarist)
156 # define OS_CODE 0x05
157 #endif
158
159 #ifdef MACOS
160 # define OS_CODE 0x07
161 #endif
162
163 #ifdef __50SERIES /* Prime/PRIMOS */
164 # define OS_CODE 0x0F
165 #endif
166
167 #ifdef TOPS20
168 # define OS_CODE 0x0a
169 #endif
170
171 #if defined(_BEOS_) || defined(RISCOS)
172 # define fdopen(fd,mode) NULL /* No fdopen() */
173 #endif
174
175 /* Common defaults */
176
177 #ifndef OS_CODE
178 # define OS_CODE 0x03 /* assume Unix */
179 #endif
180
181 #ifndef FOPEN
182 # define FOPEN(name, mode) fopen((name), (mode))
183 #endif
184
185 /* functions */
186
187 #ifdef HAVE_STRERROR
188 extern char *strerror OF((int));
189 # define zstrerror(errnum) strerror(errnum)
190 #else
191 # define zstrerror(errnum) ""
192 #endif
193
194 #if defined(pyr)
195 # define NO_MEMCPY
196 #endif
197 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
198 /* Use our own functions for small and medium model with MSC <= 5.0.
199 * You may have to use the same strategy for Borland C (untested).
200 */
201 # define NO_MEMCPY
202 #endif
203 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
204 # define HAVE_MEMCPY
205 #endif
206 #ifdef HAVE_MEMCPY
207 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
208 # define zmemcpy _fmemcpy
209 # define zmemcmp _fmemcmp
210 # define zmemzero(dest, len) _fmemset(dest, 0, len)
211 # else
212 # define zmemcpy memcpy
213 # define zmemcmp memcmp
214 # define zmemzero(dest, len) memset(dest, 0, len)
215 # endif
216 #else
217 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
218 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
219 extern void zmemzero OF((Bytef* dest, uInt len));
220 #endif
221
222 /* Diagnostic functions */
223 #ifdef DEBUG_ZLIB
224 # include <stdio.h>
225 # ifndef verbose
226 # define verbose 0
227 # endif
228 extern void z_error OF((char *m));
229 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
230 # define Trace(x) fprintf x
231 # define Tracev(x) {if (verbose) fprintf x ;}
232 # define Tracevv(x) {if (verbose>1) fprintf x ;}
233 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
234 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
235 #else
236 # define Assert(cond,msg)
237 # define Trace(x)
238 # define Tracev(x)
239 # define Tracevv(x)
240 # define Tracec(c,x)
241 # define Tracecv(c,x)
242 #endif
243
244
245 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
246
247 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
248 void zcfree OF((voidpf opaque, voidpf ptr));
249
250 #define ZALLOC(strm, items, size) \
251 (*((strm)->zalloc))((strm)->opaque, (items), (size))
252 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
253 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
254
255 #endif /* _Z_UTIL_H */
256 /* --- zutil.h */
257
258 /* +++ deflate.h */
259 /* deflate.h -- internal compression state
260 * Copyright (C) 1995-1996 Jean-loup Gailly
261 * For conditions of distribution and use, see copyright notice in zlib.h
262 */
263
264 /* WARNING: this file should *not* be used by applications. It is
265 part of the implementation of the compression library and is
266 subject to change. Applications should only use zlib.h.
267 */
268
269 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
270
271 #ifndef _DEFLATE_H
272 #define _DEFLATE_H
273
274 /* #include "zutil.h" */
275
276 /* ===========================================================================
277 * Internal compression state.
278 */
279
280 #define LENGTH_CODES 29
281 /* number of length codes, not counting the special END_BLOCK code */
282
283 #define LITERALS 256
284 /* number of literal bytes 0..255 */
285
286 #define L_CODES (LITERALS+1+LENGTH_CODES)
287 /* number of Literal or Length codes, including the END_BLOCK code */
288
289 #define D_CODES 30
290 /* number of distance codes */
291
292 #define BL_CODES 19
293 /* number of codes used to transfer the bit lengths */
294
295 #define HEAP_SIZE (2*L_CODES+1)
296 /* maximum heap size */
297
298 #define MAX_BITS 15
299 /* All codes must not exceed MAX_BITS bits */
300
301 #define INIT_STATE 42
302 #define BUSY_STATE 113
303 #define FINISH_STATE 666
304 /* Stream status */
305
306
307 /* Data structure describing a single value and its code string. */
308 typedef struct ct_data_s {
309 union {
310 ush freq; /* frequency count */
311 ush code; /* bit string */
312 } fc;
313 union {
314 ush dad; /* father node in Huffman tree */
315 ush len; /* length of bit string */
316 } dl;
317 } FAR ct_data;
318
319 #define Freq fc.freq
320 #define Code fc.code
321 #define Dad dl.dad
322 #define Len dl.len
323
324 typedef struct static_tree_desc_s static_tree_desc;
325
326 typedef struct tree_desc_s {
327 ct_data *dyn_tree; /* the dynamic tree */
328 int max_code; /* largest code with non zero frequency */
329 static_tree_desc *stat_desc; /* the corresponding static tree */
330 } FAR tree_desc;
331
332 typedef ush Pos;
333 typedef Pos FAR Posf;
334 typedef unsigned IPos;
335
336 /* A Pos is an index in the character window. We use short instead of int to
337 * save space in the various tables. IPos is used only for parameter passing.
338 */
339
340 typedef struct deflate_state {
341 z_streamp strm; /* pointer back to this zlib stream */
342 int status; /* as the name implies */
343 Bytef *pending_buf; /* output still pending */
344 ulg pending_buf_size; /* size of pending_buf */
345 Bytef *pending_out; /* next pending byte to output to the stream */
346 int pending; /* nb of bytes in the pending buffer */
347 int noheader; /* suppress zlib header and adler32 */
348 Byte data_type; /* UNKNOWN, BINARY or ASCII */
349 Byte method; /* STORED (for zip only) or DEFLATED */
350 int last_flush; /* value of flush param for previous deflate call */
351
352 /* used by deflate.c: */
353
354 uInt w_size; /* LZ77 window size (32K by default) */
355 uInt w_bits; /* log2(w_size) (8..16) */
356 uInt w_mask; /* w_size - 1 */
357
358 Bytef *window;
359 /* Sliding window. Input bytes are read into the second half of the window,
360 * and move to the first half later to keep a dictionary of at least wSize
361 * bytes. With this organization, matches are limited to a distance of
362 * wSize-MAX_MATCH bytes, but this ensures that IO is always
363 * performed with a length multiple of the block size. Also, it limits
364 * the window size to 64K, which is quite useful on MSDOS.
365 * To do: use the user input buffer as sliding window.
366 */
367
368 ulg window_size;
369 /* Actual size of window: 2*wSize, except when the user input buffer
370 * is directly used as sliding window.
371 */
372
373 Posf *prev;
374 /* Link to older string with same hash index. To limit the size of this
375 * array to 64K, this link is maintained only for the last 32K strings.
376 * An index in this array is thus a window index modulo 32K.
377 */
378
379 Posf *head; /* Heads of the hash chains or NIL. */
380
381 uInt ins_h; /* hash index of string to be inserted */
382 uInt hash_size; /* number of elements in hash table */
383 uInt hash_bits; /* log2(hash_size) */
384 uInt hash_mask; /* hash_size-1 */
385
386 uInt hash_shift;
387 /* Number of bits by which ins_h must be shifted at each input
388 * step. It must be such that after MIN_MATCH steps, the oldest
389 * byte no longer takes part in the hash key, that is:
390 * hash_shift * MIN_MATCH >= hash_bits
391 */
392
393 long block_start;
394 /* Window position at the beginning of the current output block. Gets
395 * negative when the window is moved backwards.
396 */
397
398 uInt match_length; /* length of best match */
399 IPos prev_match; /* previous match */
400 int match_available; /* set if previous match exists */
401 uInt strstart; /* start of string to insert */
402 uInt match_start; /* start of matching string */
403 uInt lookahead; /* number of valid bytes ahead in window */
404
405 uInt prev_length;
406 /* Length of the best match at previous step. Matches not greater than this
407 * are discarded. This is used in the lazy match evaluation.
408 */
409
410 uInt max_chain_length;
411 /* To speed up deflation, hash chains are never searched beyond this
412 * length. A higher limit improves compression ratio but degrades the
413 * speed.
414 */
415
416 uInt max_lazy_match;
417 /* Attempt to find a better match only when the current match is strictly
418 * smaller than this value. This mechanism is used only for compression
419 * levels >= 4.
420 */
421 # define max_insert_length max_lazy_match
422 /* Insert new strings in the hash table only if the match length is not
423 * greater than this length. This saves time but degrades compression.
424 * max_insert_length is used only for compression levels <= 3.
425 */
426
427 int level; /* compression level (1..9) */
428 int strategy; /* favor or force Huffman coding*/
429
430 uInt good_match;
431 /* Use a faster search when the previous match is longer than this */
432
433 int nice_match; /* Stop searching when current match exceeds this */
434
435 /* used by trees.c: */
436 /* Didn't use ct_data typedef below to suppress compiler warning */
437 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
438 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
439 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
440
441 struct tree_desc_s l_desc; /* desc. for literal tree */
442 struct tree_desc_s d_desc; /* desc. for distance tree */
443 struct tree_desc_s bl_desc; /* desc. for bit length tree */
444
445 ush bl_count[MAX_BITS+1];
446 /* number of codes at each bit length for an optimal tree */
447
448 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
449 int heap_len; /* number of elements in the heap */
450 int heap_max; /* element of largest frequency */
451 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
452 * The same heap array is used to build all trees.
453 */
454
455 uch depth[2*L_CODES+1];
456 /* Depth of each subtree used as tie breaker for trees of equal frequency
457 */
458
459 uchf *l_buf; /* buffer for literals or lengths */
460
461 uInt lit_bufsize;
462 /* Size of match buffer for literals/lengths. There are 4 reasons for
463 * limiting lit_bufsize to 64K:
464 * - frequencies can be kept in 16 bit counters
465 * - if compression is not successful for the first block, all input
466 * data is still in the window so we can still emit a stored block even
467 * when input comes from standard input. (This can also be done for
468 * all blocks if lit_bufsize is not greater than 32K.)
469 * - if compression is not successful for a file smaller than 64K, we can
470 * even emit a stored file instead of a stored block (saving 5 bytes).
471 * This is applicable only for zip (not gzip or zlib).
472 * - creating new Huffman trees less frequently may not provide fast
473 * adaptation to changes in the input data statistics. (Take for
474 * example a binary file with poorly compressible code followed by
475 * a highly compressible string table.) Smaller buffer sizes give
476 * fast adaptation but have of course the overhead of transmitting
477 * trees more frequently.
478 * - I can't count above 4
479 */
480
481 uInt last_lit; /* running index in l_buf */
482
483 ushf *d_buf;
484 /* Buffer for distances. To simplify the code, d_buf and l_buf have
485 * the same number of elements. To use different lengths, an extra flag
486 * array would be necessary.
487 */
488
489 ulg opt_len; /* bit length of current block with optimal trees */
490 ulg static_len; /* bit length of current block with static trees */
491 ulg compressed_len; /* total bit length of compressed file */
492 uInt matches; /* number of string matches in current block */
493 int last_eob_len; /* bit length of EOB code for last block */
494
495 #ifdef DEBUG_ZLIB
496 ulg bits_sent; /* bit length of the compressed data */
497 #endif
498
499 ush bi_buf;
500 /* Output buffer. bits are inserted starting at the bottom (least
501 * significant bits).
502 */
503 int bi_valid;
504 /* Number of valid bits in bi_buf. All bits above the last valid bit
505 * are always zero.
506 */
507
508 } FAR deflate_state;
509
510 /* Output a byte on the stream.
511 * IN assertion: there is enough room in pending_buf.
512 */
513 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
514
515
516 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
517 /* Minimum amount of lookahead, except at the end of the input file.
518 * See deflate.c for comments about the MIN_MATCH+1.
519 */
520
521 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
522 /* In order to simplify the code, particularly on 16 bit machines, match
523 * distances are limited to MAX_DIST instead of WSIZE.
524 */
525
526 /* in trees.c */
527 void _tr_init OF((deflate_state *s));
528 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
529 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
530 int eof));
531 void _tr_align OF((deflate_state *s));
532 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
533 int eof));
534 void _tr_stored_type_only OF((deflate_state *));
535
536 #endif
537 /* --- deflate.h */
538
539 /* +++ deflate.c */
540 /* deflate.c -- compress data using the deflation algorithm
541 * Copyright (C) 1995-1996 Jean-loup Gailly.
542 * For conditions of distribution and use, see copyright notice in zlib.h
543 */
544
545 /*
546 * ALGORITHM
547 *
548 * The "deflation" process depends on being able to identify portions
549 * of the input text which are identical to earlier input (within a
550 * sliding window trailing behind the input currently being processed).
551 *
552 * The most straightforward technique turns out to be the fastest for
553 * most input files: try all possible matches and select the longest.
554 * The key feature of this algorithm is that insertions into the string
555 * dictionary are very simple and thus fast, and deletions are avoided
556 * completely. Insertions are performed at each input character, whereas
557 * string matches are performed only when the previous match ends. So it
558 * is preferable to spend more time in matches to allow very fast string
559 * insertions and avoid deletions. The matching algorithm for small
560 * strings is inspired from that of Rabin & Karp. A brute force approach
561 * is used to find longer strings when a small match has been found.
562 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
563 * (by Leonid Broukhis).
564 * A previous version of this file used a more sophisticated algorithm
565 * (by Fiala and Greene) which is guaranteed to run in linear amortized
566 * time, but has a larger average cost, uses more memory and is patented.
567 * However the F&G algorithm may be faster for some highly redundant
568 * files if the parameter max_chain_length (described below) is too large.
569 *
570 * ACKNOWLEDGEMENTS
571 *
572 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
573 * I found it in 'freeze' written by Leonid Broukhis.
574 * Thanks to many people for bug reports and testing.
575 *
576 * REFERENCES
577 *
578 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
579 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
580 *
581 * A description of the Rabin and Karp algorithm is given in the book
582 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
583 *
584 * Fiala,E.R., and Greene,D.H.
585 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
586 *
587 */
588
589 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
590
591 /* #include "deflate.h" */
592
593 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
594 /*
595 If you use the zlib library in a product, an acknowledgment is welcome
596 in the documentation of your product. If for some reason you cannot
597 include such an acknowledgment, I would appreciate that you keep this
598 copyright string in the executable of your product.
599 */
600
601 /* ===========================================================================
602 * Function prototypes.
603 */
604 typedef enum {
605 need_more, /* block not completed, need more input or more output */
606 block_done, /* block flush performed */
607 finish_started, /* finish started, need only more output at next deflate */
608 finish_done /* finish done, accept no more input or output */
609 } block_state;
610
611 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
612 /* Compression function. Returns the block state after the call. */
613
614 local void fill_window OF((deflate_state *s));
615 local block_state deflate_stored OF((deflate_state *s, int flush));
616 local block_state deflate_fast OF((deflate_state *s, int flush));
617 local block_state deflate_slow OF((deflate_state *s, int flush));
618 local void lm_init OF((deflate_state *s));
619 local void putShortMSB OF((deflate_state *s, uInt b));
620 local void flush_pending OF((z_streamp strm));
621 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
622 #ifdef ASMV
623 void match_init OF((void)); /* asm code initialization */
624 uInt longest_match OF((deflate_state *s, IPos cur_match));
625 #else
626 local uInt longest_match OF((deflate_state *s, IPos cur_match));
627 #endif
628
629 #ifdef DEBUG_ZLIB
630 local void check_match OF((deflate_state *s, IPos start, IPos match,
631 int length));
632 #endif
633
634 /* ===========================================================================
635 * Local data
636 */
637
638 #define NIL 0
639 /* Tail of hash chains */
640
641 #ifndef TOO_FAR
642 # define TOO_FAR 4096
643 #endif
644 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
645
646 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
647 /* Minimum amount of lookahead, except at the end of the input file.
648 * See deflate.c for comments about the MIN_MATCH+1.
649 */
650
651 /* Values for max_lazy_match, good_match and max_chain_length, depending on
652 * the desired pack level (0..9). The values given below have been tuned to
653 * exclude worst case performance for pathological files. Better values may be
654 * found for specific files.
655 */
656 typedef struct config_s {
657 ush good_length; /* reduce lazy search above this match length */
658 ush max_lazy; /* do not perform lazy search above this match length */
659 ush nice_length; /* quit search above this match length */
660 ush max_chain;
661 compress_func func;
662 } config;
663
664 local config configuration_table[10] = {
665 /* good lazy nice chain */
666 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
667 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
668 /* 2 */ {4, 5, 16, 8, deflate_fast},
669 /* 3 */ {4, 6, 32, 32, deflate_fast},
670
671 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
672 /* 5 */ {8, 16, 32, 32, deflate_slow},
673 /* 6 */ {8, 16, 128, 128, deflate_slow},
674 /* 7 */ {8, 32, 128, 256, deflate_slow},
675 /* 8 */ {32, 128, 258, 1024, deflate_slow},
676 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
677
678 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
679 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
680 * meaning.
681 */
682
683 #define EQUAL 0
684 /* result of memcmp for equal strings */
685
686 #ifndef NO_DUMMY_DECL
687 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
688 #endif
689
690 /* ===========================================================================
691 * Update a hash value with the given input byte
692 * IN assertion: all calls to UPDATE_HASH are made with consecutive
693 * input characters, so that a running hash key can be computed from the
694 * previous key instead of complete recalculation each time.
695 */
696 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
697
698
699 /* ===========================================================================
700 * Insert string str in the dictionary and set match_head to the previous head
701 * of the hash chain (the most recent string with same hash key). Return
702 * the previous length of the hash chain.
703 * IN assertion: all calls to INSERT_STRING are made with consecutive
704 * input characters and the first MIN_MATCH bytes of str are valid
705 * (except for the last MIN_MATCH-1 bytes of the input file).
706 */
707 #define INSERT_STRING(s, str, match_head) \
708 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
709 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
710 s->head[s->ins_h] = (Pos)(str))
711
712 /* ===========================================================================
713 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
714 * prev[] will be initialized on the fly.
715 */
716 #define CLEAR_HASH(s) \
717 s->head[s->hash_size-1] = NIL; \
718 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
719
720 /* ========================================================================= */
721 int deflateInit_(strm, level, version, stream_size)
722 z_streamp strm;
723 int level;
724 const char *version;
725 int stream_size;
726 {
727 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
728 Z_DEFAULT_STRATEGY, version, stream_size);
729 /* To do: ignore strm->next_in if we use it as window */
730 }
731
732 /* ========================================================================= */
733 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
734 version, stream_size)
735 z_streamp strm;
736 int level;
737 int method;
738 int windowBits;
739 int memLevel;
740 int strategy;
741 const char *version;
742 int stream_size;
743 {
744 deflate_state *s;
745 int noheader = 0;
746 static char* my_version = ZLIB_VERSION;
747
748 ushf *overlay;
749 /* We overlay pending_buf and d_buf+l_buf. This works since the average
750 * output size for (length,distance) codes is <= 24 bits.
751 */
752
753 if (version == Z_NULL || version[0] != my_version[0] ||
754 stream_size != sizeof(z_stream)) {
755 return Z_VERSION_ERROR;
756 }
757 if (strm == Z_NULL) return Z_STREAM_ERROR;
758
759 strm->msg = Z_NULL;
760 #ifndef NO_ZCFUNCS
761 if (strm->zalloc == Z_NULL) {
762 strm->zalloc = zcalloc;
763 strm->opaque = (voidpf)0;
764 }
765 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
766 #endif
767
768 if (level == Z_DEFAULT_COMPRESSION) level = 6;
769
770 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
771 noheader = 1;
772 windowBits = -windowBits;
773 }
774 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
775 windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
776 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
777 return Z_STREAM_ERROR;
778 }
779 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
780 if (s == Z_NULL) return Z_MEM_ERROR;
781 strm->state = (struct internal_state FAR *)s;
782 s->strm = strm;
783
784 s->noheader = noheader;
785 s->w_bits = windowBits;
786 s->w_size = 1 << s->w_bits;
787 s->w_mask = s->w_size - 1;
788
789 s->hash_bits = memLevel + 7;
790 s->hash_size = 1 << s->hash_bits;
791 s->hash_mask = s->hash_size - 1;
792 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
793
794 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
795 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
796 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
797
798 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
799
800 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
801 s->pending_buf = (uchf *) overlay;
802 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
803
804 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
805 s->pending_buf == Z_NULL) {
806 strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
807 deflateEnd (strm);
808 return Z_MEM_ERROR;
809 }
810 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
811 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
812
813 s->level = level;
814 s->strategy = strategy;
815 s->method = (Byte)method;
816
817 return deflateReset(strm);
818 }
819
820 /* ========================================================================= */
821 int deflateSetDictionary (strm, dictionary, dictLength)
822 z_streamp strm;
823 const Bytef *dictionary;
824 uInt dictLength;
825 {
826 deflate_state *s;
827 uInt length = dictLength;
828 uInt n;
829 IPos hash_head = 0;
830
831 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
832 return Z_STREAM_ERROR;
833
834 s = (deflate_state *) strm->state;
835 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
836
837 strm->adler = adler32(strm->adler, dictionary, dictLength);
838
839 if (length < MIN_MATCH) return Z_OK;
840 if (length > MAX_DIST(s)) {
841 length = MAX_DIST(s);
842 #ifndef USE_DICT_HEAD
843 dictionary += dictLength - length; /* use the tail of the dictionary */
844 #endif
845 }
846 zmemcpy((charf *)s->window, dictionary, length);
847 s->strstart = length;
848 s->block_start = (long)length;
849
850 /* Insert all strings in the hash table (except for the last two bytes).
851 * s->lookahead stays null, so s->ins_h will be recomputed at the next
852 * call of fill_window.
853 */
854 s->ins_h = s->window[0];
855 UPDATE_HASH(s, s->ins_h, s->window[1]);
856 for (n = 0; n <= length - MIN_MATCH; n++) {
857 INSERT_STRING(s, n, hash_head);
858 }
859 if (hash_head) hash_head = 0; /* to make compiler happy */
860 return Z_OK;
861 }
862
863 /* ========================================================================= */
864 int deflateReset (strm)
865 z_streamp strm;
866 {
867 deflate_state *s;
868
869 if (strm == Z_NULL || strm->state == Z_NULL ||
870 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
871
872 strm->total_in = strm->total_out = 0;
873 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
874 strm->data_type = Z_UNKNOWN;
875
876 s = (deflate_state *)strm->state;
877 s->pending = 0;
878 s->pending_out = s->pending_buf;
879
880 if (s->noheader < 0) {
881 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
882 }
883 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
884 strm->adler = 1;
885 s->last_flush = Z_NO_FLUSH;
886
887 _tr_init(s);
888 lm_init(s);
889
890 return Z_OK;
891 }
892
893 /* ========================================================================= */
894 int deflateParams(strm, level, strategy)
895 z_streamp strm;
896 int level;
897 int strategy;
898 {
899 deflate_state *s;
900 compress_func func;
901 int err = Z_OK;
902
903 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
904 s = (deflate_state *) strm->state;
905
906 if (level == Z_DEFAULT_COMPRESSION) {
907 level = 6;
908 }
909 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
910 return Z_STREAM_ERROR;
911 }
912 func = configuration_table[s->level].func;
913
914 if (func != configuration_table[level].func && strm->total_in != 0) {
915 /* Flush the last buffer: */
916 err = deflate(strm, Z_PARTIAL_FLUSH);
917 }
918 if (s->level != level) {
919 s->level = level;
920 s->max_lazy_match = configuration_table[level].max_lazy;
921 s->good_match = configuration_table[level].good_length;
922 s->nice_match = configuration_table[level].nice_length;
923 s->max_chain_length = configuration_table[level].max_chain;
924 }
925 s->strategy = strategy;
926 return err;
927 }
928
929 /* =========================================================================
930 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
931 * IN assertion: the stream state is correct and there is enough room in
932 * pending_buf.
933 */
934 local void putShortMSB (s, b)
935 deflate_state *s;
936 uInt b;
937 {
938 put_byte(s, (Byte)(b >> 8));
939 put_byte(s, (Byte)(b & 0xff));
940 }
941
942 /* =========================================================================
943 * Flush as much pending output as possible. All deflate() output goes
944 * through this function so some applications may wish to modify it
945 * to avoid allocating a large strm->next_out buffer and copying into it.
946 * (See also read_buf()).
947 */
948 local void flush_pending(strm)
949 z_streamp strm;
950 {
951 deflate_state *s = (deflate_state *) strm->state;
952 unsigned len = s->pending;
953
954 if (len > strm->avail_out) len = strm->avail_out;
955 if (len == 0) return;
956
957 if (strm->next_out != Z_NULL) {
958 zmemcpy(strm->next_out, s->pending_out, len);
959 strm->next_out += len;
960 }
961 s->pending_out += len;
962 strm->total_out += len;
963 strm->avail_out -= len;
964 s->pending -= len;
965 if (s->pending == 0) {
966 s->pending_out = s->pending_buf;
967 }
968 }
969
970 /* ========================================================================= */
971 int deflate (strm, flush)
972 z_streamp strm;
973 int flush;
974 {
975 int old_flush; /* value of flush param for previous deflate call */
976 deflate_state *s;
977
978 if (strm == Z_NULL || strm->state == Z_NULL ||
979 flush > Z_FINISH || flush < 0) {
980 return Z_STREAM_ERROR;
981 }
982 s = (deflate_state *) strm->state;
983
984 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
985 (s->status == FINISH_STATE && flush != Z_FINISH)) {
986 ERR_RETURN(strm, Z_STREAM_ERROR);
987 }
988 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
989
990 s->strm = strm; /* just in case */
991 old_flush = s->last_flush;
992 s->last_flush = flush;
993
994 /* Write the zlib header */
995 if (s->status == INIT_STATE) {
996
997 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
998 uInt level_flags = (s->level-1) >> 1;
999
1000 if (level_flags > 3) level_flags = 3;
1001 header |= (level_flags << 6);
1002 if (s->strstart != 0) header |= PRESET_DICT;
1003 header += 31 - (header % 31);
1004
1005 s->status = BUSY_STATE;
1006 putShortMSB(s, header);
1007
1008 /* Save the adler32 of the preset dictionary: */
1009 if (s->strstart != 0) {
1010 putShortMSB(s, (uInt)(strm->adler >> 16));
1011 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1012 }
1013 strm->adler = 1L;
1014 }
1015
1016 /* Flush as much pending output as possible */
1017 if (s->pending != 0) {
1018 flush_pending(strm);
1019 if (strm->avail_out == 0) {
1020 /* Since avail_out is 0, deflate will be called again with
1021 * more output space, but possibly with both pending and
1022 * avail_in equal to zero. There won't be anything to do,
1023 * but this is not an error situation so make sure we
1024 * return OK instead of BUF_ERROR at next call of deflate:
1025 */
1026 s->last_flush = -1;
1027 return Z_OK;
1028 }
1029
1030 /* Make sure there is something to do and avoid duplicate consecutive
1031 * flushes. For repeated and useless calls with Z_FINISH, we keep
1032 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1033 */
1034 } else if (strm->avail_in == 0 && flush <= old_flush &&
1035 flush != Z_FINISH) {
1036 ERR_RETURN(strm, Z_BUF_ERROR);
1037 }
1038
1039 /* User must not provide more input after the first FINISH: */
1040 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1041 ERR_RETURN(strm, Z_BUF_ERROR);
1042 }
1043
1044 /* Start a new block or continue the current one.
1045 */
1046 if (strm->avail_in != 0 || s->lookahead != 0 ||
1047 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1048 block_state bstate;
1049
1050 bstate = (*(configuration_table[s->level].func))(s, flush);
1051
1052 if (bstate == finish_started || bstate == finish_done) {
1053 s->status = FINISH_STATE;
1054 }
1055 if (bstate == need_more || bstate == finish_started) {
1056 if (strm->avail_out == 0) {
1057 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1058 }
1059 return Z_OK;
1060 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1061 * of deflate should use the same flush parameter to make sure
1062 * that the flush is complete. So we don't have to output an
1063 * empty block here, this will be done at next call. This also
1064 * ensures that for a very small output buffer, we emit at most
1065 * one empty block.
1066 */
1067 }
1068 if (bstate == block_done) {
1069 if (flush == Z_PARTIAL_FLUSH) {
1070 _tr_align(s);
1071 } else if (flush == Z_PACKET_FLUSH) {
1072 /* Output just the 3-bit `stored' block type value,
1073 but not a zero length. */
1074 _tr_stored_type_only(s);
1075 } else { /* FULL_FLUSH or SYNC_FLUSH */
1076 _tr_stored_block(s, (char*)0, 0L, 0);
1077 /* For a full flush, this empty block will be recognized
1078 * as a special marker by inflate_sync().
1079 */
1080 if (flush == Z_FULL_FLUSH) {
1081 CLEAR_HASH(s); /* forget history */
1082 }
1083 }
1084 flush_pending(strm);
1085 if (strm->avail_out == 0) {
1086 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1087 return Z_OK;
1088 }
1089 }
1090 }
1091 Assert(strm->avail_out > 0, "bug2");
1092
1093 if (flush != Z_FINISH) return Z_OK;
1094 if (s->noheader) return Z_STREAM_END;
1095
1096 /* Write the zlib trailer (adler32) */
1097 putShortMSB(s, (uInt)(strm->adler >> 16));
1098 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1099 flush_pending(strm);
1100 /* If avail_out is zero, the application will call deflate again
1101 * to flush the rest.
1102 */
1103 s->noheader = -1; /* write the trailer only once! */
1104 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1105 }
1106
1107 /* ========================================================================= */
1108 int deflateEnd (strm)
1109 z_streamp strm;
1110 {
1111 int status;
1112 deflate_state *s;
1113
1114 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1115 s = (deflate_state *) strm->state;
1116
1117 status = s->status;
1118 if (status != INIT_STATE && status != BUSY_STATE &&
1119 status != FINISH_STATE) {
1120 return Z_STREAM_ERROR;
1121 }
1122
1123 /* Deallocate in reverse order of allocations: */
1124 TRY_FREE(strm, s->pending_buf);
1125 TRY_FREE(strm, s->head);
1126 TRY_FREE(strm, s->prev);
1127 TRY_FREE(strm, s->window);
1128
1129 ZFREE(strm, s);
1130 strm->state = Z_NULL;
1131
1132 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1133 }
1134
1135 /* =========================================================================
1136 * Copy the source state to the destination state.
1137 */
1138 int deflateCopy (dest, source)
1139 z_streamp dest;
1140 z_streamp source;
1141 {
1142 deflate_state *ds;
1143 deflate_state *ss;
1144 ushf *overlay;
1145
1146 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1147 return Z_STREAM_ERROR;
1148 ss = (deflate_state *) source->state;
1149
1150 *dest = *source;
1151
1152 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1153 if (ds == Z_NULL) return Z_MEM_ERROR;
1154 dest->state = (struct internal_state FAR *) ds;
1155 *ds = *ss;
1156 ds->strm = dest;
1157
1158 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1159 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1160 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1161 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1162 ds->pending_buf = (uchf *) overlay;
1163
1164 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1165 ds->pending_buf == Z_NULL) {
1166 deflateEnd (dest);
1167 return Z_MEM_ERROR;
1168 }
1169 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1170 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1171 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1172 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1173 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1174
1175 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1176 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1177 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1178
1179 ds->l_desc.dyn_tree = ds->dyn_ltree;
1180 ds->d_desc.dyn_tree = ds->dyn_dtree;
1181 ds->bl_desc.dyn_tree = ds->bl_tree;
1182
1183 return Z_OK;
1184 }
1185
1186 /* ===========================================================================
1187 * Return the number of bytes of output which are immediately available
1188 * for output from the decompressor.
1189 */
1190 int deflateOutputPending (strm)
1191 z_streamp strm;
1192 {
1193 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1194
1195 return ((deflate_state *)(strm->state))->pending;
1196 }
1197
1198 /* ===========================================================================
1199 * Read a new buffer from the current input stream, update the adler32
1200 * and total number of bytes read. All deflate() input goes through
1201 * this function so some applications may wish to modify it to avoid
1202 * allocating a large strm->next_in buffer and copying from it.
1203 * (See also flush_pending()).
1204 */
1205 local int read_buf(strm, buf, size)
1206 z_streamp strm;
1207 charf *buf;
1208 unsigned size;
1209 {
1210 unsigned len = strm->avail_in;
1211
1212 if (len > size) len = size;
1213 if (len == 0) return 0;
1214
1215 strm->avail_in -= len;
1216
1217 if (!((deflate_state *)(strm->state))->noheader) {
1218 strm->adler = adler32(strm->adler, strm->next_in, len);
1219 }
1220 zmemcpy(buf, strm->next_in, len);
1221 strm->next_in += len;
1222 strm->total_in += len;
1223
1224 return (int)len;
1225 }
1226
1227 /* ===========================================================================
1228 * Initialize the "longest match" routines for a new zlib stream
1229 */
1230 local void lm_init (s)
1231 deflate_state *s;
1232 {
1233 s->window_size = (ulg)2L*s->w_size;
1234
1235 CLEAR_HASH(s);
1236
1237 /* Set the default configuration parameters:
1238 */
1239 s->max_lazy_match = configuration_table[s->level].max_lazy;
1240 s->good_match = configuration_table[s->level].good_length;
1241 s->nice_match = configuration_table[s->level].nice_length;
1242 s->max_chain_length = configuration_table[s->level].max_chain;
1243
1244 s->strstart = 0;
1245 s->block_start = 0L;
1246 s->lookahead = 0;
1247 s->match_length = s->prev_length = MIN_MATCH-1;
1248 s->match_available = 0;
1249 s->ins_h = 0;
1250 #ifdef ASMV
1251 match_init(); /* initialize the asm code */
1252 #endif
1253 }
1254
1255 /* ===========================================================================
1256 * Set match_start to the longest match starting at the given string and
1257 * return its length. Matches shorter or equal to prev_length are discarded,
1258 * in which case the result is equal to prev_length and match_start is
1259 * garbage.
1260 * IN assertions: cur_match is the head of the hash chain for the current
1261 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1262 * OUT assertion: the match length is not greater than s->lookahead.
1263 */
1264 #ifndef ASMV
1265 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1266 * match.S. The code will be functionally equivalent.
1267 */
1268 local uInt longest_match(s, cur_match)
1269 deflate_state *s;
1270 IPos cur_match; /* current match */
1271 {
1272 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1273 register Bytef *scan = s->window + s->strstart; /* current string */
1274 register Bytef *match; /* matched string */
1275 register int len; /* length of current match */
1276 int best_len = s->prev_length; /* best match length so far */
1277 int nice_match = s->nice_match; /* stop if match long enough */
1278 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1279 s->strstart - (IPos)MAX_DIST(s) : NIL;
1280 /* Stop when cur_match becomes <= limit. To simplify the code,
1281 * we prevent matches with the string of window index 0.
1282 */
1283 Posf *prev = s->prev;
1284 uInt wmask = s->w_mask;
1285
1286 #ifdef UNALIGNED_OK
1287 /* Compare two bytes at a time. Note: this is not always beneficial.
1288 * Try with and without -DUNALIGNED_OK to check.
1289 */
1290 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1291 register ush scan_start = *(ushf*)scan;
1292 register ush scan_end = *(ushf*)(scan+best_len-1);
1293 #else
1294 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1295 register Byte scan_end1 = scan[best_len-1];
1296 register Byte scan_end = scan[best_len];
1297 #endif
1298
1299 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1300 * It is easy to get rid of this optimization if necessary.
1301 */
1302 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1303
1304 /* Do not waste too much time if we already have a good match: */
1305 if (s->prev_length >= s->good_match) {
1306 chain_length >>= 2;
1307 }
1308 /* Do not look for matches beyond the end of the input. This is necessary
1309 * to make deflate deterministic.
1310 */
1311 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1312
1313 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1314
1315 do {
1316 Assert(cur_match < s->strstart, "no future");
1317 match = s->window + cur_match;
1318
1319 /* Skip to next match if the match length cannot increase
1320 * or if the match length is less than 2:
1321 */
1322 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1323 /* This code assumes sizeof(unsigned short) == 2. Do not use
1324 * UNALIGNED_OK if your compiler uses a different size.
1325 */
1326 if (*(ushf*)(match+best_len-1) != scan_end ||
1327 *(ushf*)match != scan_start) continue;
1328
1329 /* It is not necessary to compare scan[2] and match[2] since they are
1330 * always equal when the other bytes match, given that the hash keys
1331 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1332 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1333 * lookahead only every 4th comparison; the 128th check will be made
1334 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1335 * necessary to put more guard bytes at the end of the window, or
1336 * to check more often for insufficient lookahead.
1337 */
1338 Assert(scan[2] == match[2], "scan[2]?");
1339 scan++, match++;
1340 do {
1341 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1342 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1343 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1344 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1345 scan < strend);
1346 /* The funny "do {}" generates better code on most compilers */
1347
1348 /* Here, scan <= window+strstart+257 */
1349 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1350 if (*scan == *match) scan++;
1351
1352 len = (MAX_MATCH - 1) - (int)(strend-scan);
1353 scan = strend - (MAX_MATCH-1);
1354
1355 #else /* UNALIGNED_OK */
1356
1357 if (match[best_len] != scan_end ||
1358 match[best_len-1] != scan_end1 ||
1359 *match != *scan ||
1360 *++match != scan[1]) continue;
1361
1362 /* The check at best_len-1 can be removed because it will be made
1363 * again later. (This heuristic is not always a win.)
1364 * It is not necessary to compare scan[2] and match[2] since they
1365 * are always equal when the other bytes match, given that
1366 * the hash keys are equal and that HASH_BITS >= 8.
1367 */
1368 scan += 2, match++;
1369 Assert(*scan == *match, "match[2]?");
1370
1371 /* We check for insufficient lookahead only every 8th comparison;
1372 * the 256th check will be made at strstart+258.
1373 */
1374 do {
1375 } while (*++scan == *++match && *++scan == *++match &&
1376 *++scan == *++match && *++scan == *++match &&
1377 *++scan == *++match && *++scan == *++match &&
1378 *++scan == *++match && *++scan == *++match &&
1379 scan < strend);
1380
1381 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1382
1383 len = MAX_MATCH - (int)(strend - scan);
1384 scan = strend - MAX_MATCH;
1385
1386 #endif /* UNALIGNED_OK */
1387
1388 if (len > best_len) {
1389 s->match_start = cur_match;
1390 best_len = len;
1391 if (len >= nice_match) break;
1392 #ifdef UNALIGNED_OK
1393 scan_end = *(ushf*)(scan+best_len-1);
1394 #else
1395 scan_end1 = scan[best_len-1];
1396 scan_end = scan[best_len];
1397 #endif
1398 }
1399 } while ((cur_match = prev[cur_match & wmask]) > limit
1400 && --chain_length != 0);
1401
1402 if ((uInt)best_len <= s->lookahead) return best_len;
1403 return s->lookahead;
1404 }
1405 #endif /* ASMV */
1406
1407 #ifdef DEBUG_ZLIB
1408 /* ===========================================================================
1409 * Check that the match at match_start is indeed a match.
1410 */
1411 local void check_match(s, start, match, length)
1412 deflate_state *s;
1413 IPos start, match;
1414 int length;
1415 {
1416 /* check that the match is indeed a match */
1417 if (zmemcmp((charf *)s->window + match,
1418 (charf *)s->window + start, length) != EQUAL) {
1419 fprintf(stderr, " start %u, match %u, length %d\n",
1420 start, match, length);
1421 do {
1422 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1423 } while (--length != 0);
1424 z_error("invalid match");
1425 }
1426 if (z_verbose > 1) {
1427 fprintf(stderr,"\\[%d,%d]", start-match, length);
1428 do { putc(s->window[start++], stderr); } while (--length != 0);
1429 }
1430 }
1431 #else
1432 # define check_match(s, start, match, length)
1433 #endif
1434
1435 /* ===========================================================================
1436 * Fill the window when the lookahead becomes insufficient.
1437 * Updates strstart and lookahead.
1438 *
1439 * IN assertion: lookahead < MIN_LOOKAHEAD
1440 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1441 * At least one byte has been read, or avail_in == 0; reads are
1442 * performed for at least two bytes (required for the zip translate_eol
1443 * option -- not supported here).
1444 */
1445 local void fill_window(s)
1446 deflate_state *s;
1447 {
1448 register unsigned n, m;
1449 register Posf *p;
1450 unsigned more; /* Amount of free space at the end of the window. */
1451 uInt wsize = s->w_size;
1452
1453 do {
1454 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1455
1456 /* Deal with !@#$% 64K limit: */
1457 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1458 more = wsize;
1459
1460 } else if (more == (unsigned)(-1)) {
1461 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1462 * and lookahead == 1 (input done one byte at time)
1463 */
1464 more--;
1465
1466 /* If the window is almost full and there is insufficient lookahead,
1467 * move the upper half to the lower one to make room in the upper half.
1468 */
1469 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1470
1471 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1472 (unsigned)wsize);
1473 s->match_start -= wsize;
1474 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1475 s->block_start -= (long) wsize;
1476
1477 /* Slide the hash table (could be avoided with 32 bit values
1478 at the expense of memory usage). We slide even when level == 0
1479 to keep the hash table consistent if we switch back to level > 0
1480 later. (Using level 0 permanently is not an optimal usage of
1481 zlib, so we don't care about this pathological case.)
1482 */
1483 n = s->hash_size;
1484 p = &s->head[n];
1485 do {
1486 m = *--p;
1487 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1488 } while (--n);
1489
1490 n = wsize;
1491 p = &s->prev[n];
1492 do {
1493 m = *--p;
1494 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1495 /* If n is not on any hash chain, prev[n] is garbage but
1496 * its value will never be used.
1497 */
1498 } while (--n);
1499 more += wsize;
1500 }
1501 if (s->strm->avail_in == 0) return;
1502
1503 /* If there was no sliding:
1504 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1505 * more == window_size - lookahead - strstart
1506 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1507 * => more >= window_size - 2*WSIZE + 2
1508 * In the BIG_MEM or MMAP case (not yet supported),
1509 * window_size == input_size + MIN_LOOKAHEAD &&
1510 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1511 * Otherwise, window_size == 2*WSIZE so more >= 2.
1512 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1513 */
1514 Assert(more >= 2, "more < 2");
1515
1516 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1517 more);
1518 s->lookahead += n;
1519
1520 /* Initialize the hash value now that we have some input: */
1521 if (s->lookahead >= MIN_MATCH) {
1522 s->ins_h = s->window[s->strstart];
1523 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1524 #if MIN_MATCH != 3
1525 Call UPDATE_HASH() MIN_MATCH-3 more times
1526 #endif
1527 }
1528 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1529 * but this is not important since only literal bytes will be emitted.
1530 */
1531
1532 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1533 }
1534
1535 /* ===========================================================================
1536 * Flush the current block, with given end-of-file flag.
1537 * IN assertion: strstart is set to the end of the current match.
1538 */
1539 #define FLUSH_BLOCK_ONLY(s, eof) { \
1540 _tr_flush_block(s, (s->block_start >= 0L ? \
1541 (charf *)&s->window[(unsigned)s->block_start] : \
1542 (charf *)Z_NULL), \
1543 (ulg)((long)s->strstart - s->block_start), \
1544 (eof)); \
1545 s->block_start = s->strstart; \
1546 flush_pending(s->strm); \
1547 Tracev((stderr,"[FLUSH]")); \
1548 }
1549
1550 /* Same but force premature exit if necessary. */
1551 #define FLUSH_BLOCK(s, eof) { \
1552 FLUSH_BLOCK_ONLY(s, eof); \
1553 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1554 }
1555
1556 /* ===========================================================================
1557 * Copy without compression as much as possible from the input stream, return
1558 * the current block state.
1559 * This function does not insert new strings in the dictionary since
1560 * uncompressible data is probably not useful. This function is used
1561 * only for the level=0 compression option.
1562 * NOTE: this function should be optimized to avoid extra copying from
1563 * window to pending_buf.
1564 */
1565 local block_state deflate_stored(s, flush)
1566 deflate_state *s;
1567 int flush;
1568 {
1569 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1570 * to pending_buf_size, and each stored block has a 5 byte header:
1571 */
1572 ulg max_block_size = 0xffff;
1573 ulg max_start;
1574
1575 if (max_block_size > s->pending_buf_size - 5) {
1576 max_block_size = s->pending_buf_size - 5;
1577 }
1578
1579 /* Copy as much as possible from input to output: */
1580 for (;;) {
1581 /* Fill the window as much as possible: */
1582 if (s->lookahead <= 1) {
1583
1584 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1585 s->block_start >= (long)s->w_size, "slide too late");
1586
1587 fill_window(s);
1588 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1589
1590 if (s->lookahead == 0) break; /* flush the current block */
1591 }
1592 Assert(s->block_start >= 0L, "block gone");
1593
1594 s->strstart += s->lookahead;
1595 s->lookahead = 0;
1596
1597 /* Emit a stored block if pending_buf will be full: */
1598 max_start = s->block_start + max_block_size;
1599 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1600 /* strstart == 0 is possible when wraparound on 16-bit machine */
1601 s->lookahead = (uInt)(s->strstart - max_start);
1602 s->strstart = (uInt)max_start;
1603 FLUSH_BLOCK(s, 0);
1604 }
1605 /* Flush if we may have to slide, otherwise block_start may become
1606 * negative and the data will be gone:
1607 */
1608 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1609 FLUSH_BLOCK(s, 0);
1610 }
1611 }
1612 FLUSH_BLOCK(s, flush == Z_FINISH);
1613 return flush == Z_FINISH ? finish_done : block_done;
1614 }
1615
1616 /* ===========================================================================
1617 * Compress as much as possible from the input stream, return the current
1618 * block state.
1619 * This function does not perform lazy evaluation of matches and inserts
1620 * new strings in the dictionary only for unmatched strings or for short
1621 * matches. It is used only for the fast compression options.
1622 */
1623 local block_state deflate_fast(s, flush)
1624 deflate_state *s;
1625 int flush;
1626 {
1627 IPos hash_head = NIL; /* head of the hash chain */
1628 int bflush; /* set if current block must be flushed */
1629
1630 for (;;) {
1631 /* Make sure that we always have enough lookahead, except
1632 * at the end of the input file. We need MAX_MATCH bytes
1633 * for the next match, plus MIN_MATCH bytes to insert the
1634 * string following the next match.
1635 */
1636 if (s->lookahead < MIN_LOOKAHEAD) {
1637 fill_window(s);
1638 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1639 return need_more;
1640 }
1641 if (s->lookahead == 0) break; /* flush the current block */
1642 }
1643
1644 /* Insert the string window[strstart .. strstart+2] in the
1645 * dictionary, and set hash_head to the head of the hash chain:
1646 */
1647 if (s->lookahead >= MIN_MATCH) {
1648 INSERT_STRING(s, s->strstart, hash_head);
1649 }
1650
1651 /* Find the longest match, discarding those <= prev_length.
1652 * At this point we have always match_length < MIN_MATCH
1653 */
1654 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1655 /* To simplify the code, we prevent matches with the string
1656 * of window index 0 (in particular we have to avoid a match
1657 * of the string with itself at the start of the input file).
1658 */
1659 if (s->strategy != Z_HUFFMAN_ONLY) {
1660 s->match_length = longest_match (s, hash_head);
1661 }
1662 /* longest_match() sets match_start */
1663 }
1664 if (s->match_length >= MIN_MATCH) {
1665 check_match(s, s->strstart, s->match_start, s->match_length);
1666
1667 bflush = _tr_tally(s, s->strstart - s->match_start,
1668 s->match_length - MIN_MATCH);
1669
1670 s->lookahead -= s->match_length;
1671
1672 /* Insert new strings in the hash table only if the match length
1673 * is not too large. This saves time but degrades compression.
1674 */
1675 if (s->match_length <= s->max_insert_length &&
1676 s->lookahead >= MIN_MATCH) {
1677 s->match_length--; /* string at strstart already in hash table */
1678 do {
1679 s->strstart++;
1680 INSERT_STRING(s, s->strstart, hash_head);
1681 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1682 * always MIN_MATCH bytes ahead.
1683 */
1684 } while (--s->match_length != 0);
1685 s->strstart++;
1686 } else {
1687 s->strstart += s->match_length;
1688 s->match_length = 0;
1689 s->ins_h = s->window[s->strstart];
1690 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1691 #if MIN_MATCH != 3
1692 Call UPDATE_HASH() MIN_MATCH-3 more times
1693 #endif
1694 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1695 * matter since it will be recomputed at next deflate call.
1696 */
1697 }
1698 } else {
1699 /* No match, output a literal byte */
1700 Tracevv((stderr,"%c", s->window[s->strstart]));
1701 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1702 s->lookahead--;
1703 s->strstart++;
1704 }
1705 if (bflush) FLUSH_BLOCK(s, 0);
1706 }
1707 FLUSH_BLOCK(s, flush == Z_FINISH);
1708 return flush == Z_FINISH ? finish_done : block_done;
1709 }
1710
1711 /* ===========================================================================
1712 * Same as above, but achieves better compression. We use a lazy
1713 * evaluation for matches: a match is finally adopted only if there is
1714 * no better match at the next window position.
1715 */
1716 local block_state deflate_slow(s, flush)
1717 deflate_state *s;
1718 int flush;
1719 {
1720 IPos hash_head = NIL; /* head of hash chain */
1721 int bflush; /* set if current block must be flushed */
1722
1723 /* Process the input block. */
1724 for (;;) {
1725 /* Make sure that we always have enough lookahead, except
1726 * at the end of the input file. We need MAX_MATCH bytes
1727 * for the next match, plus MIN_MATCH bytes to insert the
1728 * string following the next match.
1729 */
1730 if (s->lookahead < MIN_LOOKAHEAD) {
1731 fill_window(s);
1732 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1733 return need_more;
1734 }
1735 if (s->lookahead == 0) break; /* flush the current block */
1736 }
1737
1738 /* Insert the string window[strstart .. strstart+2] in the
1739 * dictionary, and set hash_head to the head of the hash chain:
1740 */
1741 if (s->lookahead >= MIN_MATCH) {
1742 INSERT_STRING(s, s->strstart, hash_head);
1743 }
1744
1745 /* Find the longest match, discarding those <= prev_length.
1746 */
1747 s->prev_length = s->match_length, s->prev_match = s->match_start;
1748 s->match_length = MIN_MATCH-1;
1749
1750 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1751 s->strstart - hash_head <= MAX_DIST(s)) {
1752 /* To simplify the code, we prevent matches with the string
1753 * of window index 0 (in particular we have to avoid a match
1754 * of the string with itself at the start of the input file).
1755 */
1756 if (s->strategy != Z_HUFFMAN_ONLY) {
1757 s->match_length = longest_match (s, hash_head);
1758 }
1759 /* longest_match() sets match_start */
1760
1761 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1762 (s->match_length == MIN_MATCH &&
1763 s->strstart - s->match_start > TOO_FAR))) {
1764
1765 /* If prev_match is also MIN_MATCH, match_start is garbage
1766 * but we will ignore the current match anyway.
1767 */
1768 s->match_length = MIN_MATCH-1;
1769 }
1770 }
1771 /* If there was a match at the previous step and the current
1772 * match is not better, output the previous match:
1773 */
1774 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1775 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1776 /* Do not insert strings in hash table beyond this. */
1777
1778 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1779
1780 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1781 s->prev_length - MIN_MATCH);
1782
1783 /* Insert in hash table all strings up to the end of the match.
1784 * strstart-1 and strstart are already inserted. If there is not
1785 * enough lookahead, the last two strings are not inserted in
1786 * the hash table.
1787 */
1788 s->lookahead -= s->prev_length-1;
1789 s->prev_length -= 2;
1790 do {
1791 if (++s->strstart <= max_insert) {
1792 INSERT_STRING(s, s->strstart, hash_head);
1793 }
1794 } while (--s->prev_length != 0);
1795 s->match_available = 0;
1796 s->match_length = MIN_MATCH-1;
1797 s->strstart++;
1798
1799 if (bflush) FLUSH_BLOCK(s, 0);
1800
1801 } else if (s->match_available) {
1802 /* If there was no match at the previous position, output a
1803 * single literal. If there was a match but the current match
1804 * is longer, truncate the previous match to a single literal.
1805 */
1806 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1807 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1808 FLUSH_BLOCK_ONLY(s, 0);
1809 }
1810 s->strstart++;
1811 s->lookahead--;
1812 if (s->strm->avail_out == 0) return need_more;
1813 } else {
1814 /* There is no previous match to compare with, wait for
1815 * the next step to decide.
1816 */
1817 s->match_available = 1;
1818 s->strstart++;
1819 s->lookahead--;
1820 }
1821 }
1822 Assert (flush != Z_NO_FLUSH, "no flush?");
1823 if (s->match_available) {
1824 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1825 _tr_tally (s, 0, s->window[s->strstart-1]);
1826 s->match_available = 0;
1827 }
1828 FLUSH_BLOCK(s, flush == Z_FINISH);
1829 return flush == Z_FINISH ? finish_done : block_done;
1830 }
1831 /* --- deflate.c */
1832
1833 /* +++ trees.c */
1834 /* trees.c -- output deflated data using Huffman coding
1835 * Copyright (C) 1995-1996 Jean-loup Gailly
1836 * For conditions of distribution and use, see copyright notice in zlib.h
1837 */
1838
1839 /*
1840 * ALGORITHM
1841 *
1842 * The "deflation" process uses several Huffman trees. The more
1843 * common source values are represented by shorter bit sequences.
1844 *
1845 * Each code tree is stored in a compressed form which is itself
1846 * a Huffman encoding of the lengths of all the code strings (in
1847 * ascending order by source values). The actual code strings are
1848 * reconstructed from the lengths in the inflate process, as described
1849 * in the deflate specification.
1850 *
1851 * REFERENCES
1852 *
1853 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1854 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1855 *
1856 * Storer, James A.
1857 * Data Compression: Methods and Theory, pp. 49-50.
1858 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1859 *
1860 * Sedgewick, R.
1861 * Algorithms, p290.
1862 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1863 */
1864
1865 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1866
1867 /* #include "deflate.h" */
1868
1869 #ifdef DEBUG_ZLIB
1870 # include <ctype.h>
1871 #endif
1872
1873 /* ===========================================================================
1874 * Constants
1875 */
1876
1877 #define MAX_BL_BITS 7
1878 /* Bit length codes must not exceed MAX_BL_BITS bits */
1879
1880 #define END_BLOCK 256
1881 /* end of block literal code */
1882
1883 #define REP_3_6 16
1884 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1885
1886 #define REPZ_3_10 17
1887 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1888
1889 #define REPZ_11_138 18
1890 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1891
1892 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1893 = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
1894
1895 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1896 = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
1897
1898 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1899 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1900
1901 local uch bl_order[BL_CODES]
1902 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1903 /* The lengths of the bit length codes are sent in order of decreasing
1904 * probability, to avoid transmitting the lengths for unused bit length codes.
1905 */
1906
1907 #define Buf_size (8 * 2*sizeof(char))
1908 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1909 * more than 16 bits on some systems.)
1910 */
1911
1912 /* ===========================================================================
1913 * Local data. These are initialized only once.
1914 */
1915
1916 local ct_data static_ltree[L_CODES+2];
1917 /* The static literal tree. Since the bit lengths are imposed, there is no
1918 * need for the L_CODES extra codes used during heap construction. However
1919 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1920 * below).
1921 */
1922
1923 local ct_data static_dtree[D_CODES];
1924 /* The static distance tree. (Actually a trivial tree since all codes use
1925 * 5 bits.)
1926 */
1927
1928 local uch dist_code[512];
1929 /* distance codes. The first 256 values correspond to the distances
1930 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1931 * the 15 bit distances.
1932 */
1933
1934 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1935 /* length code for each normalized match length (0 == MIN_MATCH) */
1936
1937 local int base_length[LENGTH_CODES];
1938 /* First normalized length for each code (0 = MIN_MATCH) */
1939
1940 local int base_dist[D_CODES];
1941 /* First normalized distance for each code (0 = distance of 1) */
1942
1943 struct static_tree_desc_s {
1944 ct_data *static_tree; /* static tree or NULL */
1945 intf *extra_bits; /* extra bits for each code or NULL */
1946 int extra_base; /* base index for extra_bits */
1947 int elems; /* max number of elements in the tree */
1948 int max_length; /* max bit length for the codes */
1949 };
1950
1951 local static_tree_desc static_l_desc =
1952 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1953
1954 local static_tree_desc static_d_desc =
1955 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1956
1957 local static_tree_desc static_bl_desc =
1958 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1959
1960 /* ===========================================================================
1961 * Local (static) routines in this file.
1962 */
1963
1964 local void tr_static_init OF((void));
1965 local void init_block OF((deflate_state *s));
1966 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1967 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1968 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1969 local void build_tree OF((deflate_state *s, tree_desc *desc));
1970 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1971 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1972 local int build_bl_tree OF((deflate_state *s));
1973 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1974 int blcodes));
1975 local void compress_block OF((deflate_state *s, ct_data *ltree,
1976 ct_data *dtree));
1977 local void set_data_type OF((deflate_state *s));
1978 local unsigned bi_reverse OF((unsigned value, int length));
1979 local void bi_windup OF((deflate_state *s));
1980 local void bi_flush OF((deflate_state *s));
1981 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1982 int header));
1983
1984 #ifndef DEBUG_ZLIB
1985 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1986 /* Send a code of the given tree. c and tree must not have side effects */
1987
1988 #else /* DEBUG_ZLIB */
1989 # define send_code(s, c, tree) \
1990 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1991 send_bits(s, tree[c].Code, tree[c].Len); }
1992 #endif
1993
1994 #define d_code(dist) \
1995 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1996 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1997 * must not have side effects. dist_code[256] and dist_code[257] are never
1998 * used.
1999 */
2000
2001 /* ===========================================================================
2002 * Output a short LSB first on the stream.
2003 * IN assertion: there is enough room in pendingBuf.
2004 */
2005 #define put_short(s, w) { \
2006 put_byte(s, (uch)((w) & 0xff)); \
2007 put_byte(s, (uch)((ush)(w) >> 8)); \
2008 }
2009
2010 /* ===========================================================================
2011 * Send a value on a given number of bits.
2012 * IN assertion: length <= 16 and value fits in length bits.
2013 */
2014 #ifdef DEBUG_ZLIB
2015 local void send_bits OF((deflate_state *s, int value, int length));
2016
2017 local void send_bits(s, value, length)
2018 deflate_state *s;
2019 int value; /* value to send */
2020 int length; /* number of bits */
2021 {
2022 Tracevv((stderr," l %2d v %4x ", length, value));
2023 Assert(length > 0 && length <= 15, "invalid length");
2024 s->bits_sent += (ulg)length;
2025
2026 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2027 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2028 * unused bits in value.
2029 */
2030 if (s->bi_valid > (int)Buf_size - length) {
2031 s->bi_buf |= (value << s->bi_valid);
2032 put_short(s, s->bi_buf);
2033 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2034 s->bi_valid += length - Buf_size;
2035 } else {
2036 s->bi_buf |= value << s->bi_valid;
2037 s->bi_valid += length;
2038 }
2039 }
2040 #else /* !DEBUG_ZLIB */
2041
2042 #define send_bits(s, value, length) \
2043 { int len = length;\
2044 if (s->bi_valid > (int)Buf_size - len) {\
2045 int val = value;\
2046 s->bi_buf |= (val << s->bi_valid);\
2047 put_short(s, s->bi_buf);\
2048 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2049 s->bi_valid += len - Buf_size;\
2050 } else {\
2051 s->bi_buf |= (value) << s->bi_valid;\
2052 s->bi_valid += len;\
2053 }\
2054 }
2055 #endif /* DEBUG_ZLIB */
2056
2057
2058 #define MAX(a,b) (a >= b ? a : b)
2059 /* the arguments must not have side effects */
2060
2061 /* ===========================================================================
2062 * Initialize the various 'constant' tables. In a multi-threaded environment,
2063 * this function may be called by two threads concurrently, but this is
2064 * harmless since both invocations do exactly the same thing.
2065 */
2066 local void tr_static_init()
2067 {
2068 static int static_init_done;
2069 int n; /* iterates over tree elements */
2070 int bits; /* bit counter */
2071 int length; /* length value */
2072 int code; /* code value */
2073 int dist; /* distance index */
2074 ush bl_count[MAX_BITS+1];
2075 /* number of codes at each bit length for an optimal tree */
2076
2077 if (static_init_done) return;
2078
2079 /* Initialize the mapping length (0..255) -> length code (0..28) */
2080 length = 0;
2081 for (code = 0; code < LENGTH_CODES-1; code++) {
2082 base_length[code] = length;
2083 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2084 length_code[length++] = (uch)code;
2085 }
2086 }
2087 Assert (length == 256, "tr_static_init: length != 256");
2088 /* Note that the length 255 (match length 258) can be represented
2089 * in two different ways: code 284 + 5 bits or code 285, so we
2090 * overwrite length_code[255] to use the best encoding:
2091 */
2092 length_code[length-1] = (uch)code;
2093
2094 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2095 dist = 0;
2096 for (code = 0 ; code < 16; code++) {
2097 base_dist[code] = dist;
2098 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2099 dist_code[dist++] = (uch)code;
2100 }
2101 }
2102 Assert (dist == 256, "tr_static_init: dist != 256");
2103 dist >>= 7; /* from now on, all distances are divided by 128 */
2104 for ( ; code < D_CODES; code++) {
2105 base_dist[code] = dist << 7;
2106 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2107 dist_code[256 + dist++] = (uch)code;
2108 }
2109 }
2110 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2111
2112 /* Construct the codes of the static literal tree */
2113 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2114 n = 0;
2115 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2116 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2117 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2118 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2119 /* Codes 286 and 287 do not exist, but we must include them in the
2120 * tree construction to get a canonical Huffman tree (longest code
2121 * all ones)
2122 */
2123 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2124
2125 /* The static distance tree is trivial: */
2126 for (n = 0; n < D_CODES; n++) {
2127 static_dtree[n].Len = 5;
2128 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2129 }
2130 static_init_done = 1;
2131 }
2132
2133 /* ===========================================================================
2134 * Initialize the tree data structures for a new zlib stream.
2135 */
2136 void _tr_init(s)
2137 deflate_state *s;
2138 {
2139 tr_static_init();
2140
2141 s->compressed_len = 0L;
2142
2143 s->l_desc.dyn_tree = s->dyn_ltree;
2144 s->l_desc.stat_desc = &static_l_desc;
2145
2146 s->d_desc.dyn_tree = s->dyn_dtree;
2147 s->d_desc.stat_desc = &static_d_desc;
2148
2149 s->bl_desc.dyn_tree = s->bl_tree;
2150 s->bl_desc.stat_desc = &static_bl_desc;
2151
2152 s->bi_buf = 0;
2153 s->bi_valid = 0;
2154 s->last_eob_len = 8; /* enough lookahead for inflate */
2155 #ifdef DEBUG_ZLIB
2156 s->bits_sent = 0L;
2157 #endif
2158
2159 /* Initialize the first block of the first file: */
2160 init_block(s);
2161 }
2162
2163 /* ===========================================================================
2164 * Initialize a new block.
2165 */
2166 local void init_block(s)
2167 deflate_state *s;
2168 {
2169 int n; /* iterates over tree elements */
2170
2171 /* Initialize the trees. */
2172 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2173 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2174 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2175
2176 s->dyn_ltree[END_BLOCK].Freq = 1;
2177 s->opt_len = s->static_len = 0L;
2178 s->last_lit = s->matches = 0;
2179 }
2180
2181 #define SMALLEST 1
2182 /* Index within the heap array of least frequent node in the Huffman tree */
2183
2184
2185 /* ===========================================================================
2186 * Remove the smallest element from the heap and recreate the heap with
2187 * one less element. Updates heap and heap_len.
2188 */
2189 #define pqremove(s, tree, top) \
2190 {\
2191 top = s->heap[SMALLEST]; \
2192 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2193 pqdownheap(s, tree, SMALLEST); \
2194 }
2195
2196 /* ===========================================================================
2197 * Compares to subtrees, using the tree depth as tie breaker when
2198 * the subtrees have equal frequency. This minimizes the worst case length.
2199 */
2200 #define smaller(tree, n, m, depth) \
2201 (tree[n].Freq < tree[m].Freq || \
2202 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2203
2204 /* ===========================================================================
2205 * Restore the heap property by moving down the tree starting at node k,
2206 * exchanging a node with the smallest of its two sons if necessary, stopping
2207 * when the heap property is re-established (each father smaller than its
2208 * two sons).
2209 */
2210 local void pqdownheap(s, tree, k)
2211 deflate_state *s;
2212 ct_data *tree; /* the tree to restore */
2213 int k; /* node to move down */
2214 {
2215 int v = s->heap[k];
2216 int j = k << 1; /* left son of k */
2217 while (j <= s->heap_len) {
2218 /* Set j to the smallest of the two sons: */
2219 if (j < s->heap_len &&
2220 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2221 j++;
2222 }
2223 /* Exit if v is smaller than both sons */
2224 if (smaller(tree, v, s->heap[j], s->depth)) break;
2225
2226 /* Exchange v with the smallest son */
2227 s->heap[k] = s->heap[j]; k = j;
2228
2229 /* And continue down the tree, setting j to the left son of k */
2230 j <<= 1;
2231 }
2232 s->heap[k] = v;
2233 }
2234
2235 /* ===========================================================================
2236 * Compute the optimal bit lengths for a tree and update the total bit length
2237 * for the current block.
2238 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2239 * above are the tree nodes sorted by increasing frequency.
2240 * OUT assertions: the field len is set to the optimal bit length, the
2241 * array bl_count contains the frequencies for each bit length.
2242 * The length opt_len is updated; static_len is also updated if stree is
2243 * not null.
2244 */
2245 local void gen_bitlen(s, desc)
2246 deflate_state *s;
2247 tree_desc *desc; /* the tree descriptor */
2248 {
2249 ct_data *tree = desc->dyn_tree;
2250 int max_code = desc->max_code;
2251 ct_data *stree = desc->stat_desc->static_tree;
2252 intf *extra = desc->stat_desc->extra_bits;
2253 int base = desc->stat_desc->extra_base;
2254 int max_length = desc->stat_desc->max_length;
2255 int h; /* heap index */
2256 int n, m; /* iterate over the tree elements */
2257 int bits; /* bit length */
2258 int xbits; /* extra bits */
2259 ush f; /* frequency */
2260 int overflow = 0; /* number of elements with bit length too large */
2261
2262 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2263
2264 /* In a first pass, compute the optimal bit lengths (which may
2265 * overflow in the case of the bit length tree).
2266 */
2267 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2268
2269 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2270 n = s->heap[h];
2271 bits = tree[tree[n].Dad].Len + 1;
2272 if (bits > max_length) bits = max_length, overflow++;
2273 tree[n].Len = (ush)bits;
2274 /* We overwrite tree[n].Dad which is no longer needed */
2275
2276 if (n > max_code) continue; /* not a leaf node */
2277
2278 s->bl_count[bits]++;
2279 xbits = 0;
2280 if (n >= base) xbits = extra[n-base];
2281 f = tree[n].Freq;
2282 s->opt_len += (ulg)f * (bits + xbits);
2283 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2284 }
2285 if (overflow == 0) return;
2286
2287 Trace((stderr,"\nbit length overflow\n"));
2288 /* This happens for example on obj2 and pic of the Calgary corpus */
2289
2290 /* Find the first bit length which could increase: */
2291 do {
2292 bits = max_length-1;
2293 while (s->bl_count[bits] == 0) bits--;
2294 s->bl_count[bits]--; /* move one leaf down the tree */
2295 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2296 s->bl_count[max_length]--;
2297 /* The brother of the overflow item also moves one step up,
2298 * but this does not affect bl_count[max_length]
2299 */
2300 overflow -= 2;
2301 } while (overflow > 0);
2302
2303 /* Now recompute all bit lengths, scanning in increasing frequency.
2304 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2305 * lengths instead of fixing only the wrong ones. This idea is taken
2306 * from 'ar' written by Haruhiko Okumura.)
2307 */
2308 for (bits = max_length; bits != 0; bits--) {
2309 n = s->bl_count[bits];
2310 while (n != 0) {
2311 m = s->heap[--h];
2312 if (m > max_code) continue;
2313 if (tree[m].Len != (unsigned) bits) {
2314 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2315 s->opt_len += ((long)bits - (long)tree[m].Len)
2316 *(long)tree[m].Freq;
2317 tree[m].Len = (ush)bits;
2318 }
2319 n--;
2320 }
2321 }
2322 }
2323
2324 /* ===========================================================================
2325 * Generate the codes for a given tree and bit counts (which need not be
2326 * optimal).
2327 * IN assertion: the array bl_count contains the bit length statistics for
2328 * the given tree and the field len is set for all tree elements.
2329 * OUT assertion: the field code is set for all tree elements of non
2330 * zero code length.
2331 */
2332 local void gen_codes (tree, max_code, bl_count)
2333 ct_data *tree; /* the tree to decorate */
2334 int max_code; /* largest code with non zero frequency */
2335 ushf *bl_count; /* number of codes at each bit length */
2336 {
2337 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2338 ush code = 0; /* running code value */
2339 int bits; /* bit index */
2340 int n; /* code index */
2341
2342 /* The distribution counts are first used to generate the code values
2343 * without bit reversal.
2344 */
2345 for (bits = 1; bits <= MAX_BITS; bits++) {
2346 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2347 }
2348 /* Check that the bit counts in bl_count are consistent. The last code
2349 * must be all ones.
2350 */
2351 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2352 "inconsistent bit counts");
2353 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2354
2355 for (n = 0; n <= max_code; n++) {
2356 int len = tree[n].Len;
2357 if (len == 0) continue;
2358 /* Now reverse the bits */
2359 tree[n].Code = bi_reverse(next_code[len]++, len);
2360
2361 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2362 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2363 }
2364 }
2365
2366 /* ===========================================================================
2367 * Construct one Huffman tree and assigns the code bit strings and lengths.
2368 * Update the total bit length for the current block.
2369 * IN assertion: the field freq is set for all tree elements.
2370 * OUT assertions: the fields len and code are set to the optimal bit length
2371 * and corresponding code. The length opt_len is updated; static_len is
2372 * also updated if stree is not null. The field max_code is set.
2373 */
2374 local void build_tree(s, desc)
2375 deflate_state *s;
2376 tree_desc *desc; /* the tree descriptor */
2377 {
2378 ct_data *tree = desc->dyn_tree;
2379 ct_data *stree = desc->stat_desc->static_tree;
2380 int elems = desc->stat_desc->elems;
2381 int n, m; /* iterate over heap elements */
2382 int max_code = -1; /* largest code with non zero frequency */
2383 int node; /* new node being created */
2384
2385 /* Construct the initial heap, with least frequent element in
2386 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2387 * heap[0] is not used.
2388 */
2389 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2390
2391 for (n = 0; n < elems; n++) {
2392 if (tree[n].Freq != 0) {
2393 s->heap[++(s->heap_len)] = max_code = n;
2394 s->depth[n] = 0;
2395 } else {
2396 tree[n].Len = 0;
2397 }
2398 }
2399
2400 /* The pkzip format requires that at least one distance code exists,
2401 * and that at least one bit should be sent even if there is only one
2402 * possible code. So to avoid special checks later on we force at least
2403 * two codes of non zero frequency.
2404 */
2405 while (s->heap_len < 2) {
2406 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2407 tree[node].Freq = 1;
2408 s->depth[node] = 0;
2409 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2410 /* node is 0 or 1 so it does not have extra bits */
2411 }
2412 desc->max_code = max_code;
2413
2414 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2415 * establish sub-heaps of increasing lengths:
2416 */
2417 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2418
2419 /* Construct the Huffman tree by repeatedly combining the least two
2420 * frequent nodes.
2421 */
2422 node = elems; /* next internal node of the tree */
2423 do {
2424 pqremove(s, tree, n); /* n = node of least frequency */
2425 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2426
2427 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2428 s->heap[--(s->heap_max)] = m;
2429
2430 /* Create a new node father of n and m */
2431 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2432 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2433 tree[n].Dad = tree[m].Dad = (ush)node;
2434 #ifdef DUMP_BL_TREE
2435 if (tree == s->bl_tree) {
2436 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2437 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2438 }
2439 #endif
2440 /* and insert the new node in the heap */
2441 s->heap[SMALLEST] = node++;
2442 pqdownheap(s, tree, SMALLEST);
2443
2444 } while (s->heap_len >= 2);
2445
2446 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2447
2448 /* At this point, the fields freq and dad are set. We can now
2449 * generate the bit lengths.
2450 */
2451 gen_bitlen(s, (tree_desc *)desc);
2452
2453 /* The field len is now set, we can generate the bit codes */
2454 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2455 }
2456
2457 /* ===========================================================================
2458 * Scan a literal or distance tree to determine the frequencies of the codes
2459 * in the bit length tree.
2460 */
2461 local void scan_tree (s, tree, max_code)
2462 deflate_state *s;
2463 ct_data *tree; /* the tree to be scanned */
2464 int max_code; /* and its largest code of non zero frequency */
2465 {
2466 int n; /* iterates over all tree elements */
2467 int prevlen = -1; /* last emitted length */
2468 int curlen; /* length of current code */
2469 int nextlen = tree[0].Len; /* length of next code */
2470 int count = 0; /* repeat count of the current code */
2471 int max_count = 7; /* max repeat count */
2472 int min_count = 4; /* min repeat count */
2473
2474 if (nextlen == 0) max_count = 138, min_count = 3;
2475 tree[max_code+1].Len = (ush)0xffff; /* guard */
2476
2477 for (n = 0; n <= max_code; n++) {
2478 curlen = nextlen; nextlen = tree[n+1].Len;
2479 if (++count < max_count && curlen == nextlen) {
2480 continue;
2481 } else if (count < min_count) {
2482 s->bl_tree[curlen].Freq += count;
2483 } else if (curlen != 0) {
2484 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2485 s->bl_tree[REP_3_6].Freq++;
2486 } else if (count <= 10) {
2487 s->bl_tree[REPZ_3_10].Freq++;
2488 } else {
2489 s->bl_tree[REPZ_11_138].Freq++;
2490 }
2491 count = 0; prevlen = curlen;
2492 if (nextlen == 0) {
2493 max_count = 138, min_count = 3;
2494 } else if (curlen == nextlen) {
2495 max_count = 6, min_count = 3;
2496 } else {
2497 max_count = 7, min_count = 4;
2498 }
2499 }
2500 }
2501
2502 /* ===========================================================================
2503 * Send a literal or distance tree in compressed form, using the codes in
2504 * bl_tree.
2505 */
2506 local void send_tree (s, tree, max_code)
2507 deflate_state *s;
2508 ct_data *tree; /* the tree to be scanned */
2509 int max_code; /* and its largest code of non zero frequency */
2510 {
2511 int n; /* iterates over all tree elements */
2512 int prevlen = -1; /* last emitted length */
2513 int curlen; /* length of current code */
2514 int nextlen = tree[0].Len; /* length of next code */
2515 int count = 0; /* repeat count of the current code */
2516 int max_count = 7; /* max repeat count */
2517 int min_count = 4; /* min repeat count */
2518
2519 /* tree[max_code+1].Len = -1; */ /* guard already set */
2520 if (nextlen == 0) max_count = 138, min_count = 3;
2521
2522 for (n = 0; n <= max_code; n++) {
2523 curlen = nextlen; nextlen = tree[n+1].Len;
2524 if (++count < max_count && curlen == nextlen) {
2525 continue;
2526 } else if (count < min_count) {
2527 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2528
2529 } else if (curlen != 0) {
2530 if (curlen != prevlen) {
2531 send_code(s, curlen, s->bl_tree); count--;
2532 }
2533 Assert(count >= 3 && count <= 6, " 3_6?");
2534 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2535
2536 } else if (count <= 10) {
2537 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2538
2539 } else {
2540 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2541 }
2542 count = 0; prevlen = curlen;
2543 if (nextlen == 0) {
2544 max_count = 138, min_count = 3;
2545 } else if (curlen == nextlen) {
2546 max_count = 6, min_count = 3;
2547 } else {
2548 max_count = 7, min_count = 4;
2549 }
2550 }
2551 }
2552
2553 /* ===========================================================================
2554 * Construct the Huffman tree for the bit lengths and return the index in
2555 * bl_order of the last bit length code to send.
2556 */
2557 local int build_bl_tree(s)
2558 deflate_state *s;
2559 {
2560 int max_blindex; /* index of last bit length code of non zero freq */
2561
2562 /* Determine the bit length frequencies for literal and distance trees */
2563 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2564 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2565
2566 /* Build the bit length tree: */
2567 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2568 /* opt_len now includes the length of the tree representations, except
2569 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2570 */
2571
2572 /* Determine the number of bit length codes to send. The pkzip format
2573 * requires that at least 4 bit length codes be sent. (appnote.txt says
2574 * 3 but the actual value used is 4.)
2575 */
2576 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2577 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2578 }
2579 /* Update opt_len to include the bit length tree and counts */
2580 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2581 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2582 s->opt_len, s->static_len));
2583
2584 return max_blindex;
2585 }
2586
2587 /* ===========================================================================
2588 * Send the header for a block using dynamic Huffman trees: the counts, the
2589 * lengths of the bit length codes, the literal tree and the distance tree.
2590 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2591 */
2592 local void send_all_trees(s, lcodes, dcodes, blcodes)
2593 deflate_state *s;
2594 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2595 {
2596 int rank; /* index in bl_order */
2597
2598 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2599 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2600 "too many codes");
2601 Tracev((stderr, "\nbl counts: "));
2602 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2603 send_bits(s, dcodes-1, 5);
2604 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2605 for (rank = 0; rank < blcodes; rank++) {
2606 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2607 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2608 }
2609 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2610
2611 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2612 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2613
2614 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2615 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2616 }
2617
2618 /* ===========================================================================
2619 * Send a stored block
2620 */
2621 void _tr_stored_block(s, buf, stored_len, eof)
2622 deflate_state *s;
2623 charf *buf; /* input block */
2624 ulg stored_len; /* length of input block */
2625 int eof; /* true if this is the last block for a file */
2626 {
2627 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2628 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2629 s->compressed_len += (stored_len + 4) << 3;
2630
2631 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2632 }
2633
2634 /* Send just the `stored block' type code without any length bytes or data.
2635 */
2636 void _tr_stored_type_only(s)
2637 deflate_state *s;
2638 {
2639 send_bits(s, (STORED_BLOCK << 1), 3);
2640 bi_windup(s);
2641 s->compressed_len = (s->compressed_len + 3) & ~7L;
2642 }
2643
2644
2645 /* ===========================================================================
2646 * Send one empty static block to give enough lookahead for inflate.
2647 * This takes 10 bits, of which 7 may remain in the bit buffer.
2648 * The current inflate code requires 9 bits of lookahead. If the
2649 * last two codes for the previous block (real code plus EOB) were coded
2650 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2651 * the last real code. In this case we send two empty static blocks instead
2652 * of one. (There are no problems if the previous block is stored or fixed.)
2653 * To simplify the code, we assume the worst case of last real code encoded
2654 * on one bit only.
2655 */
2656 void _tr_align(s)
2657 deflate_state *s;
2658 {
2659 send_bits(s, STATIC_TREES<<1, 3);
2660 send_code(s, END_BLOCK, static_ltree);
2661 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2662 bi_flush(s);
2663 /* Of the 10 bits for the empty block, we have already sent
2664 * (10 - bi_valid) bits. The lookahead for the last real code (before
2665 * the EOB of the previous block) was thus at least one plus the length
2666 * of the EOB plus what we have just sent of the empty static block.
2667 */
2668 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2669 send_bits(s, STATIC_TREES<<1, 3);
2670 send_code(s, END_BLOCK, static_ltree);
2671 s->compressed_len += 10L;
2672 bi_flush(s);
2673 }
2674 s->last_eob_len = 7;
2675 }
2676
2677 /* ===========================================================================
2678 * Determine the best encoding for the current block: dynamic trees, static
2679 * trees or store, and output the encoded block to the zip file. This function
2680 * returns the total compressed length for the file so far.
2681 */
2682 ulg _tr_flush_block(s, buf, stored_len, eof)
2683 deflate_state *s;
2684 charf *buf; /* input block, or NULL if too old */
2685 ulg stored_len; /* length of input block */
2686 int eof; /* true if this is the last block for a file */
2687 {
2688 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2689 int max_blindex = 0; /* index of last bit length code of non zero freq */
2690
2691 /* Build the Huffman trees unless a stored block is forced */
2692 if (s->level > 0) {
2693
2694 /* Check if the file is ascii or binary */
2695 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2696
2697 /* Construct the literal and distance trees */
2698 build_tree(s, (tree_desc *)(&(s->l_desc)));
2699 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2700 s->static_len));
2701
2702 build_tree(s, (tree_desc *)(&(s->d_desc)));
2703 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2704 s->static_len));
2705 /* At this point, opt_len and static_len are the total bit lengths of
2706 * the compressed block data, excluding the tree representations.
2707 */
2708
2709 /* Build the bit length tree for the above two trees, and get the index
2710 * in bl_order of the last bit length code to send.
2711 */
2712 max_blindex = build_bl_tree(s);
2713
2714 /* Determine the best encoding. Compute first the block length in bytes*/
2715 opt_lenb = (s->opt_len+3+7)>>3;
2716 static_lenb = (s->static_len+3+7)>>3;
2717
2718 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2719 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2720 s->last_lit));
2721
2722 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2723
2724 } else {
2725 Assert(buf != (char*)0, "lost buf");
2726 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2727 }
2728
2729 /* If compression failed and this is the first and last block,
2730 * and if the .zip file can be seeked (to rewrite the local header),
2731 * the whole file is transformed into a stored file:
2732 */
2733 #ifdef STORED_FILE_OK
2734 # ifdef FORCE_STORED_FILE
2735 if (eof && s->compressed_len == 0L) { /* force stored file */
2736 # else
2737 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2738 # endif
2739 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2740 if (buf == (charf*)0) error ("block vanished");
2741
2742 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2743 s->compressed_len = stored_len << 3;
2744 s->method = STORED;
2745 } else
2746 #endif /* STORED_FILE_OK */
2747
2748 #ifdef FORCE_STORED
2749 if (buf != (char*)0) { /* force stored block */
2750 #else
2751 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2752 /* 4: two words for the lengths */
2753 #endif
2754 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2755 * Otherwise we can't have processed more than WSIZE input bytes since
2756 * the last block flush, because compression would have been
2757 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2758 * transform a block into a stored block.
2759 */
2760 _tr_stored_block(s, buf, stored_len, eof);
2761
2762 #ifdef FORCE_STATIC
2763 } else if (static_lenb >= 0) { /* force static trees */
2764 #else
2765 } else if (static_lenb == opt_lenb) {
2766 #endif
2767 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2768 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2769 s->compressed_len += 3 + s->static_len;
2770 } else {
2771 send_bits(s, (DYN_TREES<<1)+eof, 3);
2772 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2773 max_blindex+1);
2774 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2775 s->compressed_len += 3 + s->opt_len;
2776 }
2777 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2778 init_block(s);
2779
2780 if (eof) {
2781 bi_windup(s);
2782 s->compressed_len += 7; /* align on byte boundary */
2783 }
2784 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2785 s->compressed_len-7*eof));
2786
2787 return s->compressed_len >> 3;
2788 }
2789
2790 /* ===========================================================================
2791 * Save the match info and tally the frequency counts. Return true if
2792 * the current block must be flushed.
2793 */
2794 int _tr_tally (s, dist, lc)
2795 deflate_state *s;
2796 unsigned dist; /* distance of matched string */
2797 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2798 {
2799 s->d_buf[s->last_lit] = (ush)dist;
2800 s->l_buf[s->last_lit++] = (uch)lc;
2801 if (dist == 0) {
2802 /* lc is the unmatched char */
2803 s->dyn_ltree[lc].Freq++;
2804 } else {
2805 s->matches++;
2806 /* Here, lc is the match length - MIN_MATCH */
2807 dist--; /* dist = match distance - 1 */
2808 Assert((ush)dist < (ush)MAX_DIST(s) &&
2809 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2810 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2811
2812 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2813 s->dyn_dtree[d_code(dist)].Freq++;
2814 }
2815
2816 /* Try to guess if it is profitable to stop the current block here */
2817 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2818 /* Compute an upper bound for the compressed length */
2819 ulg out_length = (ulg)s->last_lit*8L;
2820 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2821 int dcode;
2822 for (dcode = 0; dcode < D_CODES; dcode++) {
2823 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2824 (5L+extra_dbits[dcode]);
2825 }
2826 out_length >>= 3;
2827 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2828 s->last_lit, in_length, out_length,
2829 100L - out_length*100L/in_length));
2830 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2831 }
2832 return (s->last_lit == s->lit_bufsize-1);
2833 /* We avoid equality with lit_bufsize because of wraparound at 64K
2834 * on 16 bit machines and because stored blocks are restricted to
2835 * 64K-1 bytes.
2836 */
2837 }
2838
2839 /* ===========================================================================
2840 * Send the block data compressed using the given Huffman trees
2841 */
2842 local void compress_block(s, ltree, dtree)
2843 deflate_state *s;
2844 ct_data *ltree; /* literal tree */
2845 ct_data *dtree; /* distance tree */
2846 {
2847 unsigned dist; /* distance of matched string */
2848 int lc; /* match length or unmatched char (if dist == 0) */
2849 unsigned lx = 0; /* running index in l_buf */
2850 unsigned code; /* the code to send */
2851 int extra; /* number of extra bits to send */
2852
2853 if (s->last_lit != 0) do {
2854 dist = s->d_buf[lx];
2855 lc = s->l_buf[lx++];
2856 if (dist == 0) {
2857 send_code(s, lc, ltree); /* send a literal byte */
2858 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2859 } else {
2860 /* Here, lc is the match length - MIN_MATCH */
2861 code = length_code[lc];
2862 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2863 extra = extra_lbits[code];
2864 if (extra != 0) {
2865 lc -= base_length[code];
2866 send_bits(s, lc, extra); /* send the extra length bits */
2867 }
2868 dist--; /* dist is now the match distance - 1 */
2869 code = d_code(dist);
2870 Assert (code < D_CODES, "bad d_code");
2871
2872 send_code(s, code, dtree); /* send the distance code */
2873 extra = extra_dbits[code];
2874 if (extra != 0) {
2875 dist -= base_dist[code];
2876 send_bits(s, dist, extra); /* send the extra distance bits */
2877 }
2878 } /* literal or match pair ? */
2879
2880 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2881 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2882
2883 } while (lx < s->last_lit);
2884
2885 send_code(s, END_BLOCK, ltree);
2886 s->last_eob_len = ltree[END_BLOCK].Len;
2887 }
2888
2889 /* ===========================================================================
2890 * Set the data type to ASCII or BINARY, using a crude approximation:
2891 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2892 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2893 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2894 */
2895 local void set_data_type(s)
2896 deflate_state *s;
2897 {
2898 int n = 0;
2899 unsigned ascii_freq = 0;
2900 unsigned bin_freq = 0;
2901 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2902 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2903 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2904 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2905 }
2906
2907 /* ===========================================================================
2908 * Reverse the first len bits of a code, using straightforward code (a faster
2909 * method would use a table)
2910 * IN assertion: 1 <= len <= 15
2911 */
2912 local unsigned bi_reverse(code, len)
2913 unsigned code; /* the value to invert */
2914 int len; /* its bit length */
2915 {
2916 register unsigned res = 0;
2917 do {
2918 res |= code & 1;
2919 code >>= 1, res <<= 1;
2920 } while (--len > 0);
2921 return res >> 1;
2922 }
2923
2924 /* ===========================================================================
2925 * Flush the bit buffer, keeping at most 7 bits in it.
2926 */
2927 local void bi_flush(s)
2928 deflate_state *s;
2929 {
2930 if (s->bi_valid == 16) {
2931 put_short(s, s->bi_buf);
2932 s->bi_buf = 0;
2933 s->bi_valid = 0;
2934 } else if (s->bi_valid >= 8) {
2935 put_byte(s, (Byte)s->bi_buf);
2936 s->bi_buf >>= 8;
2937 s->bi_valid -= 8;
2938 }
2939 }
2940
2941 /* ===========================================================================
2942 * Flush the bit buffer and align the output on a byte boundary
2943 */
2944 local void bi_windup(s)
2945 deflate_state *s;
2946 {
2947 if (s->bi_valid > 8) {
2948 put_short(s, s->bi_buf);
2949 } else if (s->bi_valid > 0) {
2950 put_byte(s, (Byte)s->bi_buf);
2951 }
2952 s->bi_buf = 0;
2953 s->bi_valid = 0;
2954 #ifdef DEBUG_ZLIB
2955 s->bits_sent = (s->bits_sent+7) & ~7;
2956 #endif
2957 }
2958
2959 /* ===========================================================================
2960 * Copy a stored block, storing first the length and its
2961 * one's complement if requested.
2962 */
2963 local void copy_block(s, buf, len, header)
2964 deflate_state *s;
2965 charf *buf; /* the input data */
2966 unsigned len; /* its length */
2967 int header; /* true if block header must be written */
2968 {
2969 bi_windup(s); /* align on byte boundary */
2970 s->last_eob_len = 8; /* enough lookahead for inflate */
2971
2972 if (header) {
2973 put_short(s, (ush)len);
2974 put_short(s, (ush)~len);
2975 #ifdef DEBUG_ZLIB
2976 s->bits_sent += 2*16;
2977 #endif
2978 }
2979 #ifdef DEBUG_ZLIB
2980 s->bits_sent += (ulg)len<<3;
2981 #endif
2982 /* bundle up the put_byte(s, *buf++) calls */
2983 zmemcpy(&s->pending_buf[s->pending], buf, len);
2984 s->pending += len;
2985 }
2986 /* --- trees.c */
2987
2988 /* +++ inflate.c */
2989 /* inflate.c -- zlib interface to inflate modules
2990 * Copyright (C) 1995-1996 Mark Adler
2991 * For conditions of distribution and use, see copyright notice in zlib.h
2992 */
2993
2994 /* #include "zutil.h" */
2995
2996 /* +++ infblock.h */
2997 /* infblock.h -- header to use infblock.c
2998 * Copyright (C) 1995-1996 Mark Adler
2999 * For conditions of distribution and use, see copyright notice in zlib.h
3000 */
3001
3002 /* WARNING: this file should *not* be used by applications. It is
3003 part of the implementation of the compression library and is
3004 subject to change. Applications should only use zlib.h.
3005 */
3006
3007 struct inflate_blocks_state;
3008 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3009
3010 extern inflate_blocks_statef * inflate_blocks_new OF((
3011 z_streamp z,
3012 check_func c, /* check function */
3013 uInt w)); /* window size */
3014
3015 extern int inflate_blocks OF((
3016 inflate_blocks_statef *,
3017 z_streamp ,
3018 int)); /* initial return code */
3019
3020 extern void inflate_blocks_reset OF((
3021 inflate_blocks_statef *,
3022 z_streamp ,
3023 uLongf *)); /* check value on output */
3024
3025 extern int inflate_blocks_free OF((
3026 inflate_blocks_statef *,
3027 z_streamp ,
3028 uLongf *)); /* check value on output */
3029
3030 extern void inflate_set_dictionary OF((
3031 inflate_blocks_statef *s,
3032 const Bytef *d, /* dictionary */
3033 uInt n)); /* dictionary length */
3034
3035 extern int inflate_addhistory OF((
3036 inflate_blocks_statef *,
3037 z_streamp));
3038
3039 extern int inflate_packet_flush OF((
3040 inflate_blocks_statef *));
3041 /* --- infblock.h */
3042
3043 #ifndef NO_DUMMY_DECL
3044 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3045 #endif
3046
3047 /* inflate private state */
3048 struct internal_state {
3049
3050 /* mode */
3051 enum {
3052 METHOD, /* waiting for method byte */
3053 FLAG, /* waiting for flag byte */
3054 DICT4, /* four dictionary check bytes to go */
3055 DICT3, /* three dictionary check bytes to go */
3056 DICT2, /* two dictionary check bytes to go */
3057 DICT1, /* one dictionary check byte to go */
3058 DICT0, /* waiting for inflateSetDictionary */
3059 BLOCKS, /* decompressing blocks */
3060 CHECK4, /* four check bytes to go */
3061 CHECK3, /* three check bytes to go */
3062 CHECK2, /* two check bytes to go */
3063 CHECK1, /* one check byte to go */
3064 DONE, /* finished check, done */
3065 BAD} /* got an error--stay here */
3066 mode; /* current inflate mode */
3067
3068 /* mode dependent information */
3069 union {
3070 uInt method; /* if FLAGS, method byte */
3071 struct {
3072 uLong was; /* computed check value */
3073 uLong need; /* stream check value */
3074 } check; /* if CHECK, check values to compare */
3075 uInt marker; /* if BAD, inflateSync's marker bytes count */
3076 } sub; /* submode */
3077
3078 /* mode independent information */
3079 int nowrap; /* flag for no wrapper */
3080 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3081 inflate_blocks_statef
3082 *blocks; /* current inflate_blocks state */
3083
3084 };
3085
3086
3087 int inflateReset(z)
3088 z_streamp z;
3089 {
3090 uLong c;
3091
3092 if (z == Z_NULL || z->state == Z_NULL)
3093 return Z_STREAM_ERROR;
3094 z->total_in = z->total_out = 0;
3095 z->msg = Z_NULL;
3096 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3097 inflate_blocks_reset(z->state->blocks, z, &c);
3098 Trace((stderr, "inflate: reset\n"));
3099 return Z_OK;
3100 }
3101
3102
3103 int inflateEnd(z)
3104 z_streamp z;
3105 {
3106 uLong c;
3107
3108 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3109 return Z_STREAM_ERROR;
3110 if (z->state->blocks != Z_NULL)
3111 inflate_blocks_free(z->state->blocks, z, &c);
3112 ZFREE(z, z->state);
3113 z->state = Z_NULL;
3114 Trace((stderr, "inflate: end\n"));
3115 return Z_OK;
3116 }
3117
3118
3119 int inflateInit2_(z, w, version, stream_size)
3120 z_streamp z;
3121 int w;
3122 const char *version;
3123 int stream_size;
3124 {
3125 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3126 stream_size != sizeof(z_stream))
3127 return Z_VERSION_ERROR;
3128
3129 /* initialize state */
3130 if (z == Z_NULL)
3131 return Z_STREAM_ERROR;
3132 z->msg = Z_NULL;
3133 #ifndef NO_ZCFUNCS
3134 if (z->zalloc == Z_NULL)
3135 {
3136 z->zalloc = zcalloc;
3137 z->opaque = (voidpf)0;
3138 }
3139 if (z->zfree == Z_NULL) z->zfree = zcfree;
3140 #endif
3141 if ((z->state = (struct internal_state FAR *)
3142 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3143 return Z_MEM_ERROR;
3144 z->state->blocks = Z_NULL;
3145
3146 /* handle undocumented nowrap option (no zlib header or check) */
3147 z->state->nowrap = 0;
3148 if (w < 0)
3149 {
3150 w = - w;
3151 z->state->nowrap = 1;
3152 }
3153
3154 /* set window size */
3155 if (w < 8 || w > 15)
3156 {
3157 inflateEnd(z);
3158 return Z_STREAM_ERROR;
3159 }
3160 z->state->wbits = (uInt)w;
3161
3162 /* create inflate_blocks state */
3163 if ((z->state->blocks =
3164 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3165 == Z_NULL)
3166 {
3167 inflateEnd(z);
3168 return Z_MEM_ERROR;
3169 }
3170 Trace((stderr, "inflate: allocated\n"));
3171
3172 /* reset state */
3173 inflateReset(z);
3174 return Z_OK;
3175 }
3176
3177
3178 int inflateInit_(z, version, stream_size)
3179 z_streamp z;
3180 const char *version;
3181 int stream_size;
3182 {
3183 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3184 }
3185
3186
3187 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3188 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3189
3190 int inflate(z, f)
3191 z_streamp z;
3192 int f;
3193 {
3194 int r;
3195 uInt b;
3196
3197 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3198 return Z_STREAM_ERROR;
3199 r = Z_BUF_ERROR;
3200 while (1) switch (z->state->mode)
3201 {
3202 case METHOD:
3203 NEEDBYTE
3204 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3205 {
3206 z->state->mode = BAD;
3207 z->msg = (char*)"unknown compression method";
3208 z->state->sub.marker = 5; /* can't try inflateSync */
3209 break;
3210 }
3211 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3212 {
3213 z->state->mode = BAD;
3214 z->msg = (char*)"invalid window size";
3215 z->state->sub.marker = 5; /* can't try inflateSync */
3216 break;
3217 }
3218 z->state->mode = FLAG;
3219 case FLAG:
3220 NEEDBYTE
3221 b = NEXTBYTE;
3222 if (((z->state->sub.method << 8) + b) % 31)
3223 {
3224 z->state->mode = BAD;
3225 z->msg = (char*)"incorrect header check";
3226 z->state->sub.marker = 5; /* can't try inflateSync */
3227 break;
3228 }
3229 Trace((stderr, "inflate: zlib header ok\n"));
3230 if (!(b & PRESET_DICT))
3231 {
3232 z->state->mode = BLOCKS;
3233 break;
3234 }
3235 z->state->mode = DICT4;
3236 case DICT4:
3237 NEEDBYTE
3238 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3239 z->state->mode = DICT3;
3240 case DICT3:
3241 NEEDBYTE
3242 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3243 z->state->mode = DICT2;
3244 case DICT2:
3245 NEEDBYTE
3246 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3247 z->state->mode = DICT1;
3248 case DICT1:
3249 NEEDBYTE
3250 z->state->sub.check.need += (uLong)NEXTBYTE;
3251 z->adler = z->state->sub.check.need;
3252 z->state->mode = DICT0;
3253 return Z_NEED_DICT;
3254 case DICT0:
3255 z->state->mode = BAD;
3256 z->msg = (char*)"need dictionary";
3257 z->state->sub.marker = 0; /* can try inflateSync */
3258 return Z_STREAM_ERROR;
3259 case BLOCKS:
3260 r = inflate_blocks(z->state->blocks, z, r);
3261 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3262 r = inflate_packet_flush(z->state->blocks);
3263 if (r == Z_DATA_ERROR)
3264 {
3265 z->state->mode = BAD;
3266 z->state->sub.marker = 0; /* can try inflateSync */
3267 break;
3268 }
3269 if (r != Z_STREAM_END)
3270 return r;
3271 r = Z_OK;
3272 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3273 if (z->state->nowrap)
3274 {
3275 z->state->mode = DONE;
3276 break;
3277 }
3278 z->state->mode = CHECK4;
3279 case CHECK4:
3280 NEEDBYTE
3281 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3282 z->state->mode = CHECK3;
3283 case CHECK3:
3284 NEEDBYTE
3285 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3286 z->state->mode = CHECK2;
3287 case CHECK2:
3288 NEEDBYTE
3289 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3290 z->state->mode = CHECK1;
3291 case CHECK1:
3292 NEEDBYTE
3293 z->state->sub.check.need += (uLong)NEXTBYTE;
3294
3295 if (z->state->sub.check.was != z->state->sub.check.need)
3296 {
3297 z->state->mode = BAD;
3298 z->msg = (char*)"incorrect data check";
3299 z->state->sub.marker = 5; /* can't try inflateSync */
3300 break;
3301 }
3302 Trace((stderr, "inflate: zlib check ok\n"));
3303 z->state->mode = DONE;
3304 case DONE:
3305 return Z_STREAM_END;
3306 case BAD:
3307 return Z_DATA_ERROR;
3308 default:
3309 return Z_STREAM_ERROR;
3310 }
3311
3312 empty:
3313 if (f != Z_PACKET_FLUSH)
3314 return r;
3315 z->state->mode = BAD;
3316 z->msg = (char *)"need more for packet flush";
3317 z->state->sub.marker = 0; /* can try inflateSync */
3318 return Z_DATA_ERROR;
3319 }
3320
3321
3322 int inflateSetDictionary(z, dictionary, dictLength)
3323 z_streamp z;
3324 const Bytef *dictionary;
3325 uInt dictLength;
3326 {
3327 uInt length = dictLength;
3328
3329 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3330 return Z_STREAM_ERROR;
3331
3332 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3333 z->adler = 1L;
3334
3335 if (length >= ((uInt)1<<z->state->wbits))
3336 {
3337 length = (1<<z->state->wbits)-1;
3338 dictionary += dictLength - length;
3339 }
3340 inflate_set_dictionary(z->state->blocks, dictionary, length);
3341 z->state->mode = BLOCKS;
3342 return Z_OK;
3343 }
3344
3345 /*
3346 * This subroutine adds the data at next_in/avail_in to the output history
3347 * without performing any output. The output buffer must be "caught up";
3348 * i.e. no pending output (hence s->read equals s->write), and the state must
3349 * be BLOCKS (i.e. we should be willing to see the start of a series of
3350 * BLOCKS). On exit, the output will also be caught up, and the checksum
3351 * will have been updated if need be.
3352 */
3353
3354 int inflateIncomp(z)
3355 z_stream *z;
3356 {
3357 if (z->state->mode != BLOCKS)
3358 return Z_DATA_ERROR;
3359 return inflate_addhistory(z->state->blocks, z);
3360 }
3361
3362
3363 int inflateSync(z)
3364 z_streamp z;
3365 {
3366 uInt n; /* number of bytes to look at */
3367 Bytef *p; /* pointer to bytes */
3368 uInt m; /* number of marker bytes found in a row */
3369 uLong r, w; /* temporaries to save total_in and total_out */
3370
3371 /* set up */
3372 if (z == Z_NULL || z->state == Z_NULL)
3373 return Z_STREAM_ERROR;
3374 if (z->state->mode != BAD)
3375 {
3376 z->state->mode = BAD;
3377 z->state->sub.marker = 0;
3378 }
3379 if ((n = z->avail_in) == 0)
3380 return Z_BUF_ERROR;
3381 p = z->next_in;
3382 m = z->state->sub.marker;
3383
3384 /* search */
3385 while (n && m < 4)
3386 {
3387 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3388 m++;
3389 else if (*p)
3390 m = 0;
3391 else
3392 m = 4 - m;
3393 p++, n--;
3394 }
3395
3396 /* restore */
3397 z->total_in += p - z->next_in;
3398 z->next_in = p;
3399 z->avail_in = n;
3400 z->state->sub.marker = m;
3401
3402 /* return no joy or set up to restart on a new block */
3403 if (m != 4)
3404 return Z_DATA_ERROR;
3405 r = z->total_in; w = z->total_out;
3406 inflateReset(z);
3407 z->total_in = r; z->total_out = w;
3408 z->state->mode = BLOCKS;
3409 return Z_OK;
3410 }
3411
3412 #undef NEEDBYTE
3413 #undef NEXTBYTE
3414 /* --- inflate.c */
3415
3416 /* +++ infblock.c */
3417 /* infblock.c -- interpret and process block types to last block
3418 * Copyright (C) 1995-1996 Mark Adler
3419 * For conditions of distribution and use, see copyright notice in zlib.h
3420 */
3421
3422 /* #include "zutil.h" */
3423 /* #include "infblock.h" */
3424
3425 /* +++ inftrees.h */
3426 /* inftrees.h -- header to use inftrees.c
3427 * Copyright (C) 1995-1996 Mark Adler
3428 * For conditions of distribution and use, see copyright notice in zlib.h
3429 */
3430
3431 /* WARNING: this file should *not* be used by applications. It is
3432 part of the implementation of the compression library and is
3433 subject to change. Applications should only use zlib.h.
3434 */
3435
3436 /* Huffman code lookup table entry--this entry is four bytes for machines
3437 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3438
3439 typedef struct inflate_huft_s FAR inflate_huft;
3440
3441 struct inflate_huft_s {
3442 union {
3443 struct {
3444 Byte Exop; /* number of extra bits or operation */
3445 Byte Bits; /* number of bits in this code or subcode */
3446 } what;
3447 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3448 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3449 union {
3450 uInt Base; /* literal, length base, or distance base */
3451 inflate_huft *Next; /* pointer to next level of table */
3452 } more;
3453 };
3454
3455 #ifdef DEBUG_ZLIB
3456 extern uInt inflate_hufts;
3457 #endif
3458
3459 extern int inflate_trees_bits OF((
3460 uIntf *, /* 19 code lengths */
3461 uIntf *, /* bits tree desired/actual depth */
3462 inflate_huft * FAR *, /* bits tree result */
3463 z_streamp )); /* for zalloc, zfree functions */
3464
3465 extern int inflate_trees_dynamic OF((
3466 uInt, /* number of literal/length codes */
3467 uInt, /* number of distance codes */
3468 uIntf *, /* that many (total) code lengths */
3469 uIntf *, /* literal desired/actual bit depth */
3470 uIntf *, /* distance desired/actual bit depth */
3471 inflate_huft * FAR *, /* literal/length tree result */
3472 inflate_huft * FAR *, /* distance tree result */
3473 z_streamp )); /* for zalloc, zfree functions */
3474
3475 extern int inflate_trees_fixed OF((
3476 uIntf *, /* literal desired/actual bit depth */
3477 uIntf *, /* distance desired/actual bit depth */
3478 inflate_huft * FAR *, /* literal/length tree result */
3479 inflate_huft * FAR *)); /* distance tree result */
3480
3481 extern int inflate_trees_free OF((
3482 inflate_huft *, /* tables to free */
3483 z_streamp )); /* for zfree function */
3484
3485 /* --- inftrees.h */
3486
3487 /* +++ infcodes.h */
3488 /* infcodes.h -- header to use infcodes.c
3489 * Copyright (C) 1995-1996 Mark Adler
3490 * For conditions of distribution and use, see copyright notice in zlib.h
3491 */
3492
3493 /* WARNING: this file should *not* be used by applications. It is
3494 part of the implementation of the compression library and is
3495 subject to change. Applications should only use zlib.h.
3496 */
3497
3498 struct inflate_codes_state;
3499 typedef struct inflate_codes_state FAR inflate_codes_statef;
3500
3501 extern inflate_codes_statef *inflate_codes_new OF((
3502 uInt, uInt,
3503 inflate_huft *, inflate_huft *,
3504 z_streamp ));
3505
3506 extern int inflate_codes OF((
3507 inflate_blocks_statef *,
3508 z_streamp ,
3509 int));
3510
3511 extern void inflate_codes_free OF((
3512 inflate_codes_statef *,
3513 z_streamp ));
3514
3515 /* --- infcodes.h */
3516
3517 /* +++ infutil.h */
3518 /* infutil.h -- types and macros common to blocks and codes
3519 * Copyright (C) 1995-1996 Mark Adler
3520 * For conditions of distribution and use, see copyright notice in zlib.h
3521 */
3522
3523 /* WARNING: this file should *not* be used by applications. It is
3524 part of the implementation of the compression library and is
3525 subject to change. Applications should only use zlib.h.
3526 */
3527
3528 #ifndef _INFUTIL_H
3529 #define _INFUTIL_H
3530
3531 typedef enum {
3532 TYPE, /* get type bits (3, including end bit) */
3533 LENS, /* get lengths for stored */
3534 STORED, /* processing stored block */
3535 TABLE, /* get table lengths */
3536 BTREE, /* get bit lengths tree for a dynamic block */
3537 DTREE, /* get length, distance trees for a dynamic block */
3538 CODES, /* processing fixed or dynamic block */
3539 DRY, /* output remaining window bytes */
3540 DONEB, /* finished last block, done */
3541 BADB} /* got a data error--stuck here */
3542 inflate_block_mode;
3543
3544 /* inflate blocks semi-private state */
3545 struct inflate_blocks_state {
3546
3547 /* mode */
3548 inflate_block_mode mode; /* current inflate_block mode */
3549
3550 /* mode dependent information */
3551 union {
3552 uInt left; /* if STORED, bytes left to copy */
3553 struct {
3554 uInt table; /* table lengths (14 bits) */
3555 uInt index; /* index into blens (or border) */
3556 uIntf *blens; /* bit lengths of codes */
3557 uInt bb; /* bit length tree depth */
3558 inflate_huft *tb; /* bit length decoding tree */
3559 } trees; /* if DTREE, decoding info for trees */
3560 struct {
3561 inflate_huft *tl;
3562 inflate_huft *td; /* trees to free */
3563 inflate_codes_statef
3564 *codes;
3565 } decode; /* if CODES, current state */
3566 } sub; /* submode */
3567 uInt last; /* true if this block is the last block */
3568
3569 /* mode independent information */
3570 uInt bitk; /* bits in bit buffer */
3571 uLong bitb; /* bit buffer */
3572 Bytef *window; /* sliding window */
3573 Bytef *end; /* one byte after sliding window */
3574 Bytef *read; /* window read pointer */
3575 Bytef *write; /* window write pointer */
3576 check_func checkfn; /* check function */
3577 uLong check; /* check on output */
3578
3579 };
3580
3581
3582 /* defines for inflate input/output */
3583 /* update pointers and return */
3584 #define UPDBITS {s->bitb=b;s->bitk=k;}
3585 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3586 #define UPDOUT {s->write=q;}
3587 #define UPDATE {UPDBITS UPDIN UPDOUT}
3588 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3589 /* get bytes and bits */
3590 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3591 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3592 #define NEXTBYTE (n--,*p++)
3593 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3594 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3595 /* output bytes */
3596 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3597 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3598 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3599 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3600 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3601 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3602 /* load local pointers */
3603 #define LOAD {LOADIN LOADOUT}
3604
3605 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3606 extern uInt inflate_mask[17];
3607
3608 /* copy as much as possible from the sliding window to the output area */
3609 extern int inflate_flush OF((
3610 inflate_blocks_statef *,
3611 z_streamp ,
3612 int));
3613
3614 #ifndef NO_DUMMY_DECL
3615 struct internal_state {int dummy;}; /* for buggy compilers */
3616 #endif
3617
3618 #endif
3619 /* --- infutil.h */
3620
3621 #ifndef NO_DUMMY_DECL
3622 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3623 #endif
3624
3625 /* Table for deflate from PKZIP's appnote.txt. */
3626 local const uInt border[] = { /* Order of the bit length code lengths */
3627 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3628
3629 /*
3630 Notes beyond the 1.93a appnote.txt:
3631
3632 1. Distance pointers never point before the beginning of the output
3633 stream.
3634 2. Distance pointers can point back across blocks, up to 32k away.
3635 3. There is an implied maximum of 7 bits for the bit length table and
3636 15 bits for the actual data.
3637 4. If only one code exists, then it is encoded using one bit. (Zero
3638 would be more efficient, but perhaps a little confusing.) If two
3639 codes exist, they are coded using one bit each (0 and 1).
3640 5. There is no way of sending zero distance codes--a dummy must be
3641 sent if there are none. (History: a pre 2.0 version of PKZIP would
3642 store blocks with no distance codes, but this was discovered to be
3643 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3644 zero distance codes, which is sent as one code of zero bits in
3645 length.
3646 6. There are up to 286 literal/length codes. Code 256 represents the
3647 end-of-block. Note however that the static length tree defines
3648 288 codes just to fill out the Huffman codes. Codes 286 and 287
3649 cannot be used though, since there is no length base or extra bits
3650 defined for them. Similarily, there are up to 30 distance codes.
3651 However, static trees define 32 codes (all 5 bits) to fill out the
3652 Huffman codes, but the last two had better not show up in the data.
3653 7. Unzip can check dynamic Huffman blocks for complete code sets.
3654 The exception is that a single code would not be complete (see #4).
3655 8. The five bits following the block type is really the number of
3656 literal codes sent minus 257.
3657 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3658 (1+6+6). Therefore, to output three times the length, you output
3659 three codes (1+1+1), whereas to output four times the same length,
3660 you only need two codes (1+3). Hmm.
3661 10. In the tree reconstruction algorithm, Code = Code + Increment
3662 only if BitLength(i) is not zero. (Pretty obvious.)
3663 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3664 12. Note: length code 284 can represent 227-258, but length code 285
3665 really is 258. The last length deserves its own, short code
3666 since it gets used a lot in very redundant files. The length
3667 258 is special since 258 - 3 (the min match length) is 255.
3668 13. The literal/length and distance code bit lengths are read as a
3669 single stream of lengths. It is possible (and advantageous) for
3670 a repeat code (16, 17, or 18) to go across the boundary between
3671 the two sets of lengths.
3672 */
3673
3674
3675 void inflate_blocks_reset(s, z, c)
3676 inflate_blocks_statef *s;
3677 z_streamp z;
3678 uLongf *c;
3679 {
3680 if (s->checkfn != Z_NULL)
3681 *c = s->check;
3682 if (s->mode == BTREE || s->mode == DTREE)
3683 ZFREE(z, s->sub.trees.blens);
3684 if (s->mode == CODES)
3685 {
3686 inflate_codes_free(s->sub.decode.codes, z);
3687 inflate_trees_free(s->sub.decode.td, z);
3688 inflate_trees_free(s->sub.decode.tl, z);
3689 }
3690 s->mode = TYPE;
3691 s->bitk = 0;
3692 s->bitb = 0;
3693 s->read = s->write = s->window;
3694 if (s->checkfn != Z_NULL)
3695 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3696 Trace((stderr, "inflate: blocks reset\n"));
3697 }
3698
3699
3700 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3701 z_streamp z;
3702 check_func c;
3703 uInt w;
3704 {
3705 inflate_blocks_statef *s;
3706
3707 if ((s = (inflate_blocks_statef *)ZALLOC
3708 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3709 return s;
3710 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3711 {
3712 ZFREE(z, s);
3713 return Z_NULL;
3714 }
3715 s->end = s->window + w;
3716 s->checkfn = c;
3717 s->mode = TYPE;
3718 Trace((stderr, "inflate: blocks allocated\n"));
3719 inflate_blocks_reset(s, z, &s->check);
3720 return s;
3721 }
3722
3723
3724 #ifdef DEBUG_ZLIB
3725 extern uInt inflate_hufts;
3726 #endif
3727 int inflate_blocks(s, z, r)
3728 inflate_blocks_statef *s;
3729 z_streamp z;
3730 int r;
3731 {
3732 uInt t; /* temporary storage */
3733 uLong b; /* bit buffer */
3734 uInt k; /* bits in bit buffer */
3735 Bytef *p; /* input data pointer */
3736 uInt n; /* bytes available there */
3737 Bytef *q; /* output window write pointer */
3738 uInt m; /* bytes to end of window or read pointer */
3739
3740 /* copy input/output information to locals (UPDATE macro restores) */
3741 LOAD
3742
3743 /* process input based on current state */
3744 while (1) switch (s->mode)
3745 {
3746 case TYPE:
3747 NEEDBITS(3)
3748 t = (uInt)b & 7;
3749 s->last = t & 1;
3750 switch (t >> 1)
3751 {
3752 case 0: /* stored */
3753 Trace((stderr, "inflate: stored block%s\n",
3754 s->last ? " (last)" : ""));
3755 DUMPBITS(3)
3756 t = k & 7; /* go to byte boundary */
3757 DUMPBITS(t)
3758 s->mode = LENS; /* get length of stored block */
3759 break;
3760 case 1: /* fixed */
3761 Trace((stderr, "inflate: fixed codes block%s\n",
3762 s->last ? " (last)" : ""));
3763 {
3764 uInt bl, bd;
3765 inflate_huft *tl, *td;
3766
3767 inflate_trees_fixed(&bl, &bd, &tl, &td);
3768 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3769 if (s->sub.decode.codes == Z_NULL)
3770 {
3771 r = Z_MEM_ERROR;
3772 LEAVE
3773 }
3774 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3775 s->sub.decode.td = Z_NULL;
3776 }
3777 DUMPBITS(3)
3778 s->mode = CODES;
3779 break;
3780 case 2: /* dynamic */
3781 Trace((stderr, "inflate: dynamic codes block%s\n",
3782 s->last ? " (last)" : ""));
3783 DUMPBITS(3)
3784 s->mode = TABLE;
3785 break;
3786 case 3: /* illegal */
3787 DUMPBITS(3)
3788 s->mode = BADB;
3789 z->msg = (char*)"invalid block type";
3790 r = Z_DATA_ERROR;
3791 LEAVE
3792 }
3793 break;
3794 case LENS:
3795 NEEDBITS(32)
3796 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3797 {
3798 s->mode = BADB;
3799 z->msg = (char*)"invalid stored block lengths";
3800 r = Z_DATA_ERROR;
3801 LEAVE
3802 }
3803 s->sub.left = (uInt)b & 0xffff;
3804 b = k = 0; /* dump bits */
3805 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3806 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3807 break;
3808 case STORED:
3809 if (n == 0)
3810 LEAVE
3811 NEEDOUT
3812 t = s->sub.left;
3813 if (t > n) t = n;
3814 if (t > m) t = m;
3815 zmemcpy(q, p, t);
3816 p += t; n -= t;
3817 q += t; m -= t;
3818 if ((s->sub.left -= t) != 0)
3819 break;
3820 Tracev((stderr, "inflate: stored end, %lu total out\n",
3821 z->total_out + (q >= s->read ? q - s->read :
3822 (s->end - s->read) + (q - s->window))));
3823 s->mode = s->last ? DRY : TYPE;
3824 break;
3825 case TABLE:
3826 NEEDBITS(14)
3827 s->sub.trees.table = t = (uInt)b & 0x3fff;
3828 #ifndef PKZIP_BUG_WORKAROUND
3829 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3830 {
3831 s->mode = BADB;
3832 z->msg = (char*)"too many length or distance symbols";
3833 r = Z_DATA_ERROR;
3834 LEAVE
3835 }
3836 #endif
3837 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3838 if (t < 19)
3839 t = 19;
3840 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3841 {
3842 r = Z_MEM_ERROR;
3843 LEAVE
3844 }
3845 DUMPBITS(14)
3846 s->sub.trees.index = 0;
3847 Tracev((stderr, "inflate: table sizes ok\n"));
3848 s->mode = BTREE;
3849 case BTREE:
3850 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3851 {
3852 NEEDBITS(3)
3853 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3854 DUMPBITS(3)
3855 }
3856 while (s->sub.trees.index < 19)
3857 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3858 s->sub.trees.bb = 7;
3859 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3860 &s->sub.trees.tb, z);
3861 if (t != Z_OK)
3862 {
3863 ZFREE(z, s->sub.trees.blens);
3864 r = t;
3865 if (r == Z_DATA_ERROR)
3866 s->mode = BADB;
3867 LEAVE
3868 }
3869 s->sub.trees.index = 0;
3870 Tracev((stderr, "inflate: bits tree ok\n"));
3871 s->mode = DTREE;
3872 case DTREE:
3873 while (t = s->sub.trees.table,
3874 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3875 {
3876 inflate_huft *h;
3877 uInt i, j, c;
3878
3879 t = s->sub.trees.bb;
3880 NEEDBITS(t)
3881 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3882 t = h->word.what.Bits;
3883 c = h->more.Base;
3884 if (c < 16)
3885 {
3886 DUMPBITS(t)
3887 s->sub.trees.blens[s->sub.trees.index++] = c;
3888 }
3889 else /* c == 16..18 */
3890 {
3891 i = c == 18 ? 7 : c - 14;
3892 j = c == 18 ? 11 : 3;
3893 NEEDBITS(t + i)
3894 DUMPBITS(t)
3895 j += (uInt)b & inflate_mask[i];
3896 DUMPBITS(i)
3897 i = s->sub.trees.index;
3898 t = s->sub.trees.table;
3899 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3900 (c == 16 && i < 1))
3901 {
3902 inflate_trees_free(s->sub.trees.tb, z);
3903 ZFREE(z, s->sub.trees.blens);
3904 s->mode = BADB;
3905 z->msg = (char*)"invalid bit length repeat";
3906 r = Z_DATA_ERROR;
3907 LEAVE
3908 }
3909 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3910 do {
3911 s->sub.trees.blens[i++] = c;
3912 } while (--j);
3913 s->sub.trees.index = i;
3914 }
3915 }
3916 inflate_trees_free(s->sub.trees.tb, z);
3917 s->sub.trees.tb = Z_NULL;
3918 {
3919 uInt bl, bd;
3920 inflate_huft *tl, *td;
3921 inflate_codes_statef *c;
3922
3923 bl = 9; /* must be <= 9 for lookahead assumptions */
3924 bd = 6; /* must be <= 9 for lookahead assumptions */
3925 t = s->sub.trees.table;
3926 #ifdef DEBUG_ZLIB
3927 inflate_hufts = 0;
3928 #endif
3929 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3930 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3931 ZFREE(z, s->sub.trees.blens);
3932 if (t != Z_OK)
3933 {
3934 if (t == (uInt)Z_DATA_ERROR)
3935 s->mode = BADB;
3936 r = t;
3937 LEAVE
3938 }
3939 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3940 inflate_hufts, sizeof(inflate_huft)));
3941 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3942 {
3943 inflate_trees_free(td, z);
3944 inflate_trees_free(tl, z);
3945 r = Z_MEM_ERROR;
3946 LEAVE
3947 }
3948 s->sub.decode.codes = c;
3949 s->sub.decode.tl = tl;
3950 s->sub.decode.td = td;
3951 }
3952 s->mode = CODES;
3953 case CODES:
3954 UPDATE
3955 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3956 return inflate_flush(s, z, r);
3957 r = Z_OK;
3958 inflate_codes_free(s->sub.decode.codes, z);
3959 inflate_trees_free(s->sub.decode.td, z);
3960 inflate_trees_free(s->sub.decode.tl, z);
3961 LOAD
3962 Tracev((stderr, "inflate: codes end, %lu total out\n",
3963 z->total_out + (q >= s->read ? q - s->read :
3964 (s->end - s->read) + (q - s->window))));
3965 if (!s->last)
3966 {
3967 s->mode = TYPE;
3968 break;
3969 }
3970 if (k > 7) /* return unused byte, if any */
3971 {
3972 Assert(k < 16, "inflate_codes grabbed too many bytes")
3973 k -= 8;
3974 n++;
3975 p--; /* can always return one */
3976 }
3977 s->mode = DRY;
3978 case DRY:
3979 FLUSH
3980 if (s->read != s->write)
3981 LEAVE
3982 s->mode = DONEB;
3983 case DONEB:
3984 r = Z_STREAM_END;
3985 LEAVE
3986 case BADB:
3987 r = Z_DATA_ERROR;
3988 LEAVE
3989 default:
3990 r = Z_STREAM_ERROR;
3991 LEAVE
3992 }
3993 }
3994
3995
3996 int inflate_blocks_free(s, z, c)
3997 inflate_blocks_statef *s;
3998 z_streamp z;
3999 uLongf *c;
4000 {
4001 inflate_blocks_reset(s, z, c);
4002 ZFREE(z, s->window);
4003 ZFREE(z, s);
4004 Trace((stderr, "inflate: blocks freed\n"));
4005 return Z_OK;
4006 }
4007
4008
4009 void inflate_set_dictionary(s, d, n)
4010 inflate_blocks_statef *s;
4011 const Bytef *d;
4012 uInt n;
4013 {
4014 zmemcpy((charf *)s->window, d, n);
4015 s->read = s->write = s->window + n;
4016 }
4017
4018 /*
4019 * This subroutine adds the data at next_in/avail_in to the output history
4020 * without performing any output. The output buffer must be "caught up";
4021 * i.e. no pending output (hence s->read equals s->write), and the state must
4022 * be BLOCKS (i.e. we should be willing to see the start of a series of
4023 * BLOCKS). On exit, the output will also be caught up, and the checksum
4024 * will have been updated if need be.
4025 */
4026 int inflate_addhistory(s, z)
4027 inflate_blocks_statef *s;
4028 z_stream *z;
4029 {
4030 uLong b; /* bit buffer */ /* NOT USED HERE */
4031 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4032 uInt t; /* temporary storage */
4033 Bytef *p; /* input data pointer */
4034 uInt n; /* bytes available there */
4035 Bytef *q; /* output window write pointer */
4036 uInt m; /* bytes to end of window or read pointer */
4037
4038 if (s->read != s->write)
4039 return Z_STREAM_ERROR;
4040 if (s->mode != TYPE)
4041 return Z_DATA_ERROR;
4042
4043 /* we're ready to rock */
4044 LOAD
4045 /* while there is input ready, copy to output buffer, moving
4046 * pointers as needed.
4047 */
4048 while (n) {
4049 t = n; /* how many to do */
4050 /* is there room until end of buffer? */
4051 if (t > m) t = m;
4052 /* update check information */
4053 if (s->checkfn != Z_NULL)
4054 s->check = (*s->checkfn)(s->check, q, t);
4055 zmemcpy(q, p, t);
4056 q += t;
4057 p += t;
4058 n -= t;
4059 z->total_out += t;
4060 s->read = q; /* drag read pointer forward */
4061 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4062 if (q == s->end) {
4063 s->read = q = s->window;
4064 m = WAVAIL;
4065 }
4066 }
4067 UPDATE
4068 return Z_OK;
4069 }
4070
4071
4072 /*
4073 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4074 * a `stored' block type value but not the (zero) length bytes.
4075 */
4076 int inflate_packet_flush(s)
4077 inflate_blocks_statef *s;
4078 {
4079 if (s->mode != LENS)
4080 return Z_DATA_ERROR;
4081 s->mode = TYPE;
4082 return Z_OK;
4083 }
4084 /* --- infblock.c */
4085
4086 /* +++ inftrees.c */
4087 /* inftrees.c -- generate Huffman trees for efficient decoding
4088 * Copyright (C) 1995-1996 Mark Adler
4089 * For conditions of distribution and use, see copyright notice in zlib.h
4090 */
4091
4092 /* #include "zutil.h" */
4093 /* #include "inftrees.h" */
4094
4095 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4096 /*
4097 If you use the zlib library in a product, an acknowledgment is welcome
4098 in the documentation of your product. If for some reason you cannot
4099 include such an acknowledgment, I would appreciate that you keep this
4100 copyright string in the executable of your product.
4101 */
4102
4103 #ifndef NO_DUMMY_DECL
4104 struct internal_state {int dummy;}; /* for buggy compilers */
4105 #endif
4106
4107 /* simplify the use of the inflate_huft type with some defines */
4108 #define base more.Base
4109 #define next more.Next
4110 #define exop word.what.Exop
4111 #define bits word.what.Bits
4112
4113
4114 local int huft_build OF((
4115 uIntf *, /* code lengths in bits */
4116 uInt, /* number of codes */
4117 uInt, /* number of "simple" codes */
4118 const uIntf *, /* list of base values for non-simple codes */
4119 const uIntf *, /* list of extra bits for non-simple codes */
4120 inflate_huft * FAR*,/* result: starting table */
4121 uIntf *, /* maximum lookup bits (returns actual) */
4122 z_streamp )); /* for zalloc function */
4123
4124 local voidpf falloc OF((
4125 voidpf, /* opaque pointer (not used) */
4126 uInt, /* number of items */
4127 uInt)); /* size of item */
4128
4129 /* Tables for deflate from PKZIP's appnote.txt. */
4130 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4131 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4132 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4133 /* see note #13 above about 258 */
4134 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4135 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4136 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4137 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4138 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4139 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4140 8193, 12289, 16385, 24577};
4141 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4142 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4143 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4144 12, 12, 13, 13};
4145
4146 /*
4147 Huffman code decoding is performed using a multi-level table lookup.
4148 The fastest way to decode is to simply build a lookup table whose
4149 size is determined by the longest code. However, the time it takes
4150 to build this table can also be a factor if the data being decoded
4151 is not very long. The most common codes are necessarily the
4152 shortest codes, so those codes dominate the decoding time, and hence
4153 the speed. The idea is you can have a shorter table that decodes the
4154 shorter, more probable codes, and then point to subsidiary tables for
4155 the longer codes. The time it costs to decode the longer codes is
4156 then traded against the time it takes to make longer tables.
4157
4158 This results of this trade are in the variables lbits and dbits
4159 below. lbits is the number of bits the first level table for literal/
4160 length codes can decode in one step, and dbits is the same thing for
4161 the distance codes. Subsequent tables are also less than or equal to
4162 those sizes. These values may be adjusted either when all of the
4163 codes are shorter than that, in which case the longest code length in
4164 bits is used, or when the shortest code is *longer* than the requested
4165 table size, in which case the length of the shortest code in bits is
4166 used.
4167
4168 There are two different values for the two tables, since they code a
4169 different number of possibilities each. The literal/length table
4170 codes 286 possible values, or in a flat code, a little over eight
4171 bits. The distance table codes 30 possible values, or a little less
4172 than five bits, flat. The optimum values for speed end up being
4173 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4174 The optimum values may differ though from machine to machine, and
4175 possibly even between compilers. Your mileage may vary.
4176 */
4177
4178
4179 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4180 #define BMAX 15 /* maximum bit length of any code */
4181 #define N_MAX 288 /* maximum number of codes in any set */
4182
4183 #ifdef DEBUG_ZLIB
4184 uInt inflate_hufts;
4185 #endif
4186
4187 local int huft_build(b, n, s, d, e, t, m, zs)
4188 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4189 uInt n; /* number of codes (assumed <= N_MAX) */
4190 uInt s; /* number of simple-valued codes (0..s-1) */
4191 const uIntf *d; /* list of base values for non-simple codes */
4192 const uIntf *e; /* list of extra bits for non-simple codes */
4193 inflate_huft * FAR *t; /* result: starting table */
4194 uIntf *m; /* maximum lookup bits, returns actual */
4195 z_streamp zs; /* for zalloc function */
4196 /* Given a list of code lengths and a maximum table size, make a set of
4197 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4198 if the given code set is incomplete (the tables are still built in this
4199 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4200 lengths), or Z_MEM_ERROR if not enough memory. */
4201 {
4202
4203 uInt a; /* counter for codes of length k */
4204 uInt c[BMAX+1]; /* bit length count table */
4205 uInt f; /* i repeats in table every f entries */
4206 int g; /* maximum code length */
4207 int h; /* table level */
4208 register uInt i; /* counter, current code */
4209 register uInt j; /* counter */
4210 register int k; /* number of bits in current code */
4211 int l; /* bits per table (returned in m) */
4212 register uIntf *p; /* pointer into c[], b[], or v[] */
4213 inflate_huft *q; /* points to current table */
4214 struct inflate_huft_s r; /* table entry for structure assignment */
4215 inflate_huft *u[BMAX]; /* table stack */
4216 uInt v[N_MAX]; /* values in order of bit length */
4217 register int w; /* bits before this table == (l * h) */
4218 uInt x[BMAX+1]; /* bit offsets, then code stack */
4219 uIntf *xp; /* pointer into x */
4220 int y; /* number of dummy codes added */
4221 uInt z; /* number of entries in current table */
4222
4223
4224 /* Generate counts for each bit length */
4225 p = c;
4226 #define C0 *p++ = 0;
4227 #define C2 C0 C0 C0 C0
4228 #define C4 C2 C2 C2 C2
4229 C4 /* clear c[]--assume BMAX+1 is 16 */
4230 p = b; i = n;
4231 do {
4232 c[*p++]++; /* assume all entries <= BMAX */
4233 } while (--i);
4234 if (c[0] == n) /* null input--all zero length codes */
4235 {
4236 *t = (inflate_huft *)Z_NULL;
4237 *m = 0;
4238 return Z_OK;
4239 }
4240
4241
4242 /* Find minimum and maximum length, bound *m by those */
4243 l = *m;
4244 for (j = 1; j <= BMAX; j++)
4245 if (c[j])
4246 break;
4247 k = j; /* minimum code length */
4248 if ((uInt)l < j)
4249 l = j;
4250 for (i = BMAX; i; i--)
4251 if (c[i])
4252 break;
4253 g = i; /* maximum code length */
4254 if ((uInt)l > i)
4255 l = i;
4256 *m = l;
4257
4258
4259 /* Adjust last length count to fill out codes, if needed */
4260 for (y = 1 << j; j < i; j++, y <<= 1)
4261 if ((y -= c[j]) < 0)
4262 return Z_DATA_ERROR;
4263 if ((y -= c[i]) < 0)
4264 return Z_DATA_ERROR;
4265 c[i] += y;
4266
4267
4268 /* Generate starting offsets into the value table for each length */
4269 x[1] = j = 0;
4270 p = c + 1; xp = x + 2;
4271 while (--i) { /* note that i == g from above */
4272 *xp++ = (j += *p++);
4273 }
4274
4275
4276 /* Make a table of values in order of bit lengths */
4277 p = b; i = 0;
4278 do {
4279 if ((j = *p++) != 0)
4280 v[x[j]++] = i;
4281 } while (++i < n);
4282 n = x[g]; /* set n to length of v */
4283
4284
4285 /* Generate the Huffman codes and for each, make the table entries */
4286 x[0] = i = 0; /* first Huffman code is zero */
4287 p = v; /* grab values in bit order */
4288 h = -1; /* no tables yet--level -1 */
4289 w = -l; /* bits decoded == (l * h) */
4290 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4291 q = (inflate_huft *)Z_NULL; /* ditto */
4292 z = 0; /* ditto */
4293
4294 /* go through the bit lengths (k already is bits in shortest code) */
4295 for (; k <= g; k++)
4296 {
4297 a = c[k];
4298 while (a--)
4299 {
4300 /* here i is the Huffman code of length k bits for value *p */
4301 /* make tables up to required level */
4302 while (k > w + l)
4303 {
4304 h++;
4305 w += l; /* previous table always l bits */
4306
4307 /* compute minimum size table less than or equal to l bits */
4308 z = g - w;
4309 z = z > (uInt)l ? l : z; /* table size upper limit */
4310 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4311 { /* too few codes for k-w bit table */
4312 f -= a + 1; /* deduct codes from patterns left */
4313 xp = c + k;
4314 if (j < z)
4315 while (++j < z) /* try smaller tables up to z bits */
4316 {
4317 if ((f <<= 1) <= *++xp)
4318 break; /* enough codes to use up j bits */
4319 f -= *xp; /* else deduct codes from patterns */
4320 }
4321 }
4322 z = 1 << j; /* table entries for j-bit table */
4323
4324 /* allocate and link in new table */
4325 if ((q = (inflate_huft *)ZALLOC
4326 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4327 {
4328 if (h)
4329 inflate_trees_free(u[0], zs);
4330 return Z_MEM_ERROR; /* not enough memory */
4331 }
4332 #ifdef DEBUG_ZLIB
4333 inflate_hufts += z + 1;
4334 #endif
4335 *t = q + 1; /* link to list for huft_free() */
4336 *(t = &(q->next)) = Z_NULL;
4337 u[h] = ++q; /* table starts after link */
4338
4339 /* connect to last table, if there is one */
4340 if (h)
4341 {
4342 x[h] = i; /* save pattern for backing up */
4343 r.bits = (Byte)l; /* bits to dump before this table */
4344 r.exop = (Byte)j; /* bits in this table */
4345 r.next = q; /* pointer to this table */
4346 j = i >> (w - l); /* (get around Turbo C bug) */
4347 u[h-1][j] = r; /* connect to last table */
4348 }
4349 }
4350
4351 /* set up table entry in r */
4352 r.bits = (Byte)(k - w);
4353 if (p >= v + n)
4354 r.exop = 128 + 64; /* out of values--invalid code */
4355 else if (*p < s)
4356 {
4357 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4358 r.base = *p++; /* simple code is just the value */
4359 }
4360 else
4361 {
4362 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4363 r.base = d[*p++ - s];
4364 }
4365
4366 /* fill code-like entries with r */
4367 f = 1 << (k - w);
4368 for (j = i >> w; j < z; j += f)
4369 q[j] = r;
4370
4371 /* backwards increment the k-bit code i */
4372 for (j = 1 << (k - 1); i & j; j >>= 1)
4373 i ^= j;
4374 i ^= j;
4375
4376 /* backup over finished tables */
4377 while ((i & ((1 << w) - 1)) != x[h])
4378 {
4379 h--; /* don't need to update q */
4380 w -= l;
4381 }
4382 }
4383 }
4384
4385
4386 /* Return Z_BUF_ERROR if we were given an incomplete table */
4387 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4388 }
4389
4390
4391 int inflate_trees_bits(c, bb, tb, z)
4392 uIntf *c; /* 19 code lengths */
4393 uIntf *bb; /* bits tree desired/actual depth */
4394 inflate_huft * FAR *tb; /* bits tree result */
4395 z_streamp z; /* for zfree function */
4396 {
4397 int r;
4398
4399 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4400 if (r == Z_DATA_ERROR)
4401 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4402 else if (r == Z_BUF_ERROR || *bb == 0)
4403 {
4404 inflate_trees_free(*tb, z);
4405 z->msg = (char*)"incomplete dynamic bit lengths tree";
4406 r = Z_DATA_ERROR;
4407 }
4408 return r;
4409 }
4410
4411
4412 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4413 uInt nl; /* number of literal/length codes */
4414 uInt nd; /* number of distance codes */
4415 uIntf *c; /* that many (total) code lengths */
4416 uIntf *bl; /* literal desired/actual bit depth */
4417 uIntf *bd; /* distance desired/actual bit depth */
4418 inflate_huft * FAR *tl; /* literal/length tree result */
4419 inflate_huft * FAR *td; /* distance tree result */
4420 z_streamp z; /* for zfree function */
4421 {
4422 int r;
4423
4424 /* build literal/length tree */
4425 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4426 if (r != Z_OK || *bl == 0)
4427 {
4428 if (r == Z_DATA_ERROR)
4429 z->msg = (char*)"oversubscribed literal/length tree";
4430 else if (r != Z_MEM_ERROR)
4431 {
4432 inflate_trees_free(*tl, z);
4433 z->msg = (char*)"incomplete literal/length tree";
4434 r = Z_DATA_ERROR;
4435 }
4436 return r;
4437 }
4438
4439 /* build distance tree */
4440 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4441 if (r != Z_OK || (*bd == 0 && nl > 257))
4442 {
4443 if (r == Z_DATA_ERROR)
4444 z->msg = (char*)"oversubscribed distance tree";
4445 else if (r == Z_BUF_ERROR) {
4446 #ifdef PKZIP_BUG_WORKAROUND
4447 r = Z_OK;
4448 }
4449 #else
4450 inflate_trees_free(*td, z);
4451 z->msg = (char*)"incomplete distance tree";
4452 r = Z_DATA_ERROR;
4453 }
4454 else if (r != Z_MEM_ERROR)
4455 {
4456 z->msg = (char*)"empty distance tree with lengths";
4457 r = Z_DATA_ERROR;
4458 }
4459 inflate_trees_free(*tl, z);
4460 return r;
4461 #endif
4462 }
4463
4464 /* done */
4465 return Z_OK;
4466 }
4467
4468
4469 /* build fixed tables only once--keep them here */
4470 local int fixed_built = 0;
4471 #define FIXEDH 530 /* number of hufts used by fixed tables */
4472 local inflate_huft fixed_mem[FIXEDH];
4473 local uInt fixed_bl;
4474 local uInt fixed_bd;
4475 local inflate_huft *fixed_tl;
4476 local inflate_huft *fixed_td;
4477
4478
4479 local voidpf falloc(q, n, s)
4480 voidpf q; /* opaque pointer */
4481 uInt n; /* number of items */
4482 uInt s; /* size of item */
4483 {
4484 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4485 "inflate_trees falloc overflow");
4486 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4487 return (voidpf)(fixed_mem + *(intf *)q);
4488 }
4489
4490
4491 int inflate_trees_fixed(bl, bd, tl, td)
4492 uIntf *bl; /* literal desired/actual bit depth */
4493 uIntf *bd; /* distance desired/actual bit depth */
4494 inflate_huft * FAR *tl; /* literal/length tree result */
4495 inflate_huft * FAR *td; /* distance tree result */
4496 {
4497 /* build fixed tables if not already (multiple overlapped executions ok) */
4498 if (!fixed_built)
4499 {
4500 int k; /* temporary variable */
4501 unsigned c[288]; /* length list for huft_build */
4502 z_stream z; /* for falloc function */
4503 int f = FIXEDH; /* number of hufts left in fixed_mem */
4504
4505 /* set up fake z_stream for memory routines */
4506 z.zalloc = falloc;
4507 z.zfree = Z_NULL;
4508 z.opaque = (voidpf)&f;
4509
4510 /* literal table */
4511 for (k = 0; k < 144; k++)
4512 c[k] = 8;
4513 for (; k < 256; k++)
4514 c[k] = 9;
4515 for (; k < 280; k++)
4516 c[k] = 7;
4517 for (; k < 288; k++)
4518 c[k] = 8;
4519 fixed_bl = 7;
4520 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4521
4522 /* distance table */
4523 for (k = 0; k < 30; k++)
4524 c[k] = 5;
4525 fixed_bd = 5;
4526 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4527
4528 /* done */
4529 Assert(f == 0, "invalid build of fixed tables");
4530 fixed_built = 1;
4531 }
4532 *bl = fixed_bl;
4533 *bd = fixed_bd;
4534 *tl = fixed_tl;
4535 *td = fixed_td;
4536 return Z_OK;
4537 }
4538
4539
4540 int inflate_trees_free(t, z)
4541 inflate_huft *t; /* table to free */
4542 z_streamp z; /* for zfree function */
4543 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4544 list of the tables it made, with the links in a dummy first entry of
4545 each table. */
4546 {
4547 register inflate_huft *p, *q, *r;
4548
4549 /* Reverse linked list */
4550 p = Z_NULL;
4551 q = t;
4552 while (q != Z_NULL)
4553 {
4554 r = (q - 1)->next;
4555 (q - 1)->next = p;
4556 p = q;
4557 q = r;
4558 }
4559 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4560 while (p != Z_NULL)
4561 {
4562 q = (--p)->next;
4563 ZFREE(z,p);
4564 p = q;
4565 }
4566 return Z_OK;
4567 }
4568 /* --- inftrees.c */
4569
4570 /* +++ infcodes.c */
4571 /* infcodes.c -- process literals and length/distance pairs
4572 * Copyright (C) 1995-1996 Mark Adler
4573 * For conditions of distribution and use, see copyright notice in zlib.h
4574 */
4575
4576 /* #include "zutil.h" */
4577 /* #include "inftrees.h" */
4578 /* #include "infblock.h" */
4579 /* #include "infcodes.h" */
4580 /* #include "infutil.h" */
4581
4582 /* +++ inffast.h */
4583 /* inffast.h -- header to use inffast.c
4584 * Copyright (C) 1995-1996 Mark Adler
4585 * For conditions of distribution and use, see copyright notice in zlib.h
4586 */
4587
4588 /* WARNING: this file should *not* be used by applications. It is
4589 part of the implementation of the compression library and is
4590 subject to change. Applications should only use zlib.h.
4591 */
4592
4593 extern int inflate_fast OF((
4594 uInt,
4595 uInt,
4596 inflate_huft *,
4597 inflate_huft *,
4598 inflate_blocks_statef *,
4599 z_streamp ));
4600 /* --- inffast.h */
4601
4602 /* simplify the use of the inflate_huft type with some defines */
4603 #define base more.Base
4604 #define next more.Next
4605 #define exop word.what.Exop
4606 #define bits word.what.Bits
4607
4608 /* inflate codes private state */
4609 struct inflate_codes_state {
4610
4611 /* mode */
4612 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4613 START, /* x: set up for LEN */
4614 LEN, /* i: get length/literal/eob next */
4615 LENEXT, /* i: getting length extra (have base) */
4616 DIST, /* i: get distance next */
4617 DISTEXT, /* i: getting distance extra */
4618 COPY, /* o: copying bytes in window, waiting for space */
4619 LIT, /* o: got literal, waiting for output space */
4620 WASH, /* o: got eob, possibly still output waiting */
4621 END, /* x: got eob and all data flushed */
4622 BADCODE} /* x: got error */
4623 mode; /* current inflate_codes mode */
4624
4625 /* mode dependent information */
4626 uInt len;
4627 union {
4628 struct {
4629 inflate_huft *tree; /* pointer into tree */
4630 uInt need; /* bits needed */
4631 } code; /* if LEN or DIST, where in tree */
4632 uInt lit; /* if LIT, literal */
4633 struct {
4634 uInt get; /* bits to get for extra */
4635 uInt dist; /* distance back to copy from */
4636 } copy; /* if EXT or COPY, where and how much */
4637 } sub; /* submode */
4638
4639 /* mode independent information */
4640 Byte lbits; /* ltree bits decoded per branch */
4641 Byte dbits; /* dtree bits decoder per branch */
4642 inflate_huft *ltree; /* literal/length/eob tree */
4643 inflate_huft *dtree; /* distance tree */
4644
4645 };
4646
4647
4648 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4649 uInt bl, bd;
4650 inflate_huft *tl;
4651 inflate_huft *td; /* need separate declaration for Borland C++ */
4652 z_streamp z;
4653 {
4654 inflate_codes_statef *c;
4655
4656 if ((c = (inflate_codes_statef *)
4657 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4658 {
4659 c->mode = START;
4660 c->lbits = (Byte)bl;
4661 c->dbits = (Byte)bd;
4662 c->ltree = tl;
4663 c->dtree = td;
4664 Tracev((stderr, "inflate: codes new\n"));
4665 }
4666 return c;
4667 }
4668
4669
4670 int inflate_codes(s, z, r)
4671 inflate_blocks_statef *s;
4672 z_streamp z;
4673 int r;
4674 {
4675 uInt j; /* temporary storage */
4676 inflate_huft *t; /* temporary pointer */
4677 uInt e; /* extra bits or operation */
4678 uLong b; /* bit buffer */
4679 uInt k; /* bits in bit buffer */
4680 Bytef *p; /* input data pointer */
4681 uInt n; /* bytes available there */
4682 Bytef *q; /* output window write pointer */
4683 uInt m; /* bytes to end of window or read pointer */
4684 Bytef *f; /* pointer to copy strings from */
4685 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4686
4687 /* copy input/output information to locals (UPDATE macro restores) */
4688 LOAD
4689
4690 /* process input and output based on current state */
4691 while (1) switch (c->mode)
4692 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4693 case START: /* x: set up for LEN */
4694 #ifndef SLOW
4695 if (m >= 258 && n >= 10)
4696 {
4697 UPDATE
4698 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4699 LOAD
4700 if (r != Z_OK)
4701 {
4702 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4703 break;
4704 }
4705 }
4706 #endif /* !SLOW */
4707 c->sub.code.need = c->lbits;
4708 c->sub.code.tree = c->ltree;
4709 c->mode = LEN;
4710 case LEN: /* i: get length/literal/eob next */
4711 j = c->sub.code.need;
4712 NEEDBITS(j)
4713 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4714 DUMPBITS(t->bits)
4715 e = (uInt)(t->exop);
4716 if (e == 0) /* literal */
4717 {
4718 c->sub.lit = t->base;
4719 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4720 "inflate: literal '%c'\n" :
4721 "inflate: literal 0x%02x\n", t->base));
4722 c->mode = LIT;
4723 break;
4724 }
4725 if (e & 16) /* length */
4726 {
4727 c->sub.copy.get = e & 15;
4728 c->len = t->base;
4729 c->mode = LENEXT;
4730 break;
4731 }
4732 if ((e & 64) == 0) /* next table */
4733 {
4734 c->sub.code.need = e;
4735 c->sub.code.tree = t->next;
4736 break;
4737 }
4738 if (e & 32) /* end of block */
4739 {
4740 Tracevv((stderr, "inflate: end of block\n"));
4741 c->mode = WASH;
4742 break;
4743 }
4744 c->mode = BADCODE; /* invalid code */
4745 z->msg = (char*)"invalid literal/length code";
4746 r = Z_DATA_ERROR;
4747 LEAVE
4748 case LENEXT: /* i: getting length extra (have base) */
4749 j = c->sub.copy.get;
4750 NEEDBITS(j)
4751 c->len += (uInt)b & inflate_mask[j];
4752 DUMPBITS(j)
4753 c->sub.code.need = c->dbits;
4754 c->sub.code.tree = c->dtree;
4755 Tracevv((stderr, "inflate: length %u\n", c->len));
4756 c->mode = DIST;
4757 case DIST: /* i: get distance next */
4758 j = c->sub.code.need;
4759 NEEDBITS(j)
4760 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4761 DUMPBITS(t->bits)
4762 e = (uInt)(t->exop);
4763 if (e & 16) /* distance */
4764 {
4765 c->sub.copy.get = e & 15;
4766 c->sub.copy.dist = t->base;
4767 c->mode = DISTEXT;
4768 break;
4769 }
4770 if ((e & 64) == 0) /* next table */
4771 {
4772 c->sub.code.need = e;
4773 c->sub.code.tree = t->next;
4774 break;
4775 }
4776 c->mode = BADCODE; /* invalid code */
4777 z->msg = (char*)"invalid distance code";
4778 r = Z_DATA_ERROR;
4779 LEAVE
4780 case DISTEXT: /* i: getting distance extra */
4781 j = c->sub.copy.get;
4782 NEEDBITS(j)
4783 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4784 DUMPBITS(j)
4785 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4786 c->mode = COPY;
4787 case COPY: /* o: copying bytes in window, waiting for space */
4788 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4789 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4790 s->end - (c->sub.copy.dist - (q - s->window)) :
4791 q - c->sub.copy.dist;
4792 #else
4793 f = q - c->sub.copy.dist;
4794 if ((uInt)(q - s->window) < c->sub.copy.dist)
4795 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4796 #endif
4797 while (c->len)
4798 {
4799 NEEDOUT
4800 OUTBYTE(*f++)
4801 if (f == s->end)
4802 f = s->window;
4803 c->len--;
4804 }
4805 c->mode = START;
4806 break;
4807 case LIT: /* o: got literal, waiting for output space */
4808 NEEDOUT
4809 OUTBYTE(c->sub.lit)
4810 c->mode = START;
4811 break;
4812 case WASH: /* o: got eob, possibly more output */
4813 FLUSH
4814 if (s->read != s->write)
4815 LEAVE
4816 c->mode = END;
4817 case END:
4818 r = Z_STREAM_END;
4819 LEAVE
4820 case BADCODE: /* x: got error */
4821 r = Z_DATA_ERROR;
4822 LEAVE
4823 default:
4824 r = Z_STREAM_ERROR;
4825 LEAVE
4826 }
4827 }
4828
4829
4830 void inflate_codes_free(c, z)
4831 inflate_codes_statef *c;
4832 z_streamp z;
4833 {
4834 ZFREE(z, c);
4835 Tracev((stderr, "inflate: codes free\n"));
4836 }
4837 /* --- infcodes.c */
4838
4839 /* +++ infutil.c */
4840 /* inflate_util.c -- data and routines common to blocks and codes
4841 * Copyright (C) 1995-1996 Mark Adler
4842 * For conditions of distribution and use, see copyright notice in zlib.h
4843 */
4844
4845 /* #include "zutil.h" */
4846 /* #include "infblock.h" */
4847 /* #include "inftrees.h" */
4848 /* #include "infcodes.h" */
4849 /* #include "infutil.h" */
4850
4851 #ifndef NO_DUMMY_DECL
4852 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4853 #endif
4854
4855 /* And'ing with mask[n] masks the lower n bits */
4856 uInt inflate_mask[17] = {
4857 0x0000,
4858 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4859 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4860 };
4861
4862
4863 /* copy as much as possible from the sliding window to the output area */
4864 int inflate_flush(s, z, r)
4865 inflate_blocks_statef *s;
4866 z_streamp z;
4867 int r;
4868 {
4869 uInt n;
4870 Bytef *p;
4871 Bytef *q;
4872
4873 /* local copies of source and destination pointers */
4874 p = z->next_out;
4875 q = s->read;
4876
4877 /* compute number of bytes to copy as far as end of window */
4878 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4879 if (n > z->avail_out) n = z->avail_out;
4880 if (n && r == Z_BUF_ERROR) r = Z_OK;
4881
4882 /* update counters */
4883 z->avail_out -= n;
4884 z->total_out += n;
4885
4886 /* update check information */
4887 if (s->checkfn != Z_NULL)
4888 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4889
4890 /* copy as far as end of window */
4891 if (p != Z_NULL) {
4892 zmemcpy(p, q, n);
4893 p += n;
4894 }
4895 q += n;
4896
4897 /* see if more to copy at beginning of window */
4898 if (q == s->end)
4899 {
4900 /* wrap pointers */
4901 q = s->window;
4902 if (s->write == s->end)
4903 s->write = s->window;
4904
4905 /* compute bytes to copy */
4906 n = (uInt)(s->write - q);
4907 if (n > z->avail_out) n = z->avail_out;
4908 if (n && r == Z_BUF_ERROR) r = Z_OK;
4909
4910 /* update counters */
4911 z->avail_out -= n;
4912 z->total_out += n;
4913
4914 /* update check information */
4915 if (s->checkfn != Z_NULL)
4916 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4917
4918 /* copy */
4919 if (p != Z_NULL) {
4920 zmemcpy(p, q, n);
4921 p += n;
4922 }
4923 q += n;
4924 }
4925
4926 /* update pointers */
4927 z->next_out = p;
4928 s->read = q;
4929
4930 /* done */
4931 return r;
4932 }
4933 /* --- infutil.c */
4934
4935 /* +++ inffast.c */
4936 /* inffast.c -- process literals and length/distance pairs fast
4937 * Copyright (C) 1995-1996 Mark Adler
4938 * For conditions of distribution and use, see copyright notice in zlib.h
4939 */
4940
4941 /* #include "zutil.h" */
4942 /* #include "inftrees.h" */
4943 /* #include "infblock.h" */
4944 /* #include "infcodes.h" */
4945 /* #include "infutil.h" */
4946 /* #include "inffast.h" */
4947
4948 #ifndef NO_DUMMY_DECL
4949 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4950 #endif
4951
4952 /* simplify the use of the inflate_huft type with some defines */
4953 #define base more.Base
4954 #define next more.Next
4955 #define exop word.what.Exop
4956 #define bits word.what.Bits
4957
4958 /* macros for bit input with no checking and for returning unused bytes */
4959 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4960 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4961
4962 /* Called with number of bytes left to write in window at least 258
4963 (the maximum string length) and number of input bytes available
4964 at least ten. The ten bytes are six bytes for the longest length/
4965 distance pair plus four bytes for overloading the bit buffer. */
4966
4967 int inflate_fast(bl, bd, tl, td, s, z)
4968 uInt bl, bd;
4969 inflate_huft *tl;
4970 inflate_huft *td; /* need separate declaration for Borland C++ */
4971 inflate_blocks_statef *s;
4972 z_streamp z;
4973 {
4974 inflate_huft *t; /* temporary pointer */
4975 uInt e; /* extra bits or operation */
4976 uLong b; /* bit buffer */
4977 uInt k; /* bits in bit buffer */
4978 Bytef *p; /* input data pointer */
4979 uInt n; /* bytes available there */
4980 Bytef *q; /* output window write pointer */
4981 uInt m; /* bytes to end of window or read pointer */
4982 uInt ml; /* mask for literal/length tree */
4983 uInt md; /* mask for distance tree */
4984 uInt c; /* bytes to copy */
4985 uInt d; /* distance back to copy from */
4986 Bytef *r; /* copy source pointer */
4987
4988 /* load input, output, bit values */
4989 LOAD
4990
4991 /* initialize masks */
4992 ml = inflate_mask[bl];
4993 md = inflate_mask[bd];
4994
4995 /* do until not enough input or output space for fast loop */
4996 do { /* assume called with m >= 258 && n >= 10 */
4997 /* get literal/length code */
4998 GRABBITS(20) /* max bits for literal/length code */
4999 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5000 {
5001 DUMPBITS(t->bits)
5002 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5003 "inflate: * literal '%c'\n" :
5004 "inflate: * literal 0x%02x\n", t->base));
5005 *q++ = (Byte)t->base;
5006 m--;
5007 continue;
5008 }
5009 do {
5010 DUMPBITS(t->bits)
5011 if (e & 16)
5012 {
5013 /* get extra bits for length */
5014 e &= 15;
5015 c = t->base + ((uInt)b & inflate_mask[e]);
5016 DUMPBITS(e)
5017 Tracevv((stderr, "inflate: * length %u\n", c));
5018
5019 /* decode distance base of block to copy */
5020 GRABBITS(15); /* max bits for distance code */
5021 e = (t = td + ((uInt)b & md))->exop;
5022 do {
5023 DUMPBITS(t->bits)
5024 if (e & 16)
5025 {
5026 /* get extra bits to add to distance base */
5027 e &= 15;
5028 GRABBITS(e) /* get extra bits (up to 13) */
5029 d = t->base + ((uInt)b & inflate_mask[e]);
5030 DUMPBITS(e)
5031 Tracevv((stderr, "inflate: * distance %u\n", d));
5032
5033 /* do the copy */
5034 m -= c;
5035 if ((uInt)(q - s->window) >= d) /* offset before dest */
5036 { /* just copy */
5037 r = q - d;
5038 *q++ = *r++; c--; /* minimum count is three, */
5039 *q++ = *r++; c--; /* so unroll loop a little */
5040 }
5041 else /* else offset after destination */
5042 {
5043 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5044 r = s->end - e; /* pointer to offset */
5045 if (c > e) /* if source crosses, */
5046 {
5047 c -= e; /* copy to end of window */
5048 do {
5049 *q++ = *r++;
5050 } while (--e);
5051 r = s->window; /* copy rest from start of window */
5052 }
5053 }
5054 do { /* copy all or what's left */
5055 *q++ = *r++;
5056 } while (--c);
5057 break;
5058 }
5059 else if ((e & 64) == 0)
5060 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5061 else
5062 {
5063 z->msg = (char*)"invalid distance code";
5064 UNGRAB
5065 UPDATE
5066 return Z_DATA_ERROR;
5067 }
5068 } while (1);
5069 break;
5070 }
5071 if ((e & 64) == 0)
5072 {
5073 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5074 {
5075 DUMPBITS(t->bits)
5076 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5077 "inflate: * literal '%c'\n" :
5078 "inflate: * literal 0x%02x\n", t->base));
5079 *q++ = (Byte)t->base;
5080 m--;
5081 break;
5082 }
5083 }
5084 else if (e & 32)
5085 {
5086 Tracevv((stderr, "inflate: * end of block\n"));
5087 UNGRAB
5088 UPDATE
5089 return Z_STREAM_END;
5090 }
5091 else
5092 {
5093 z->msg = (char*)"invalid literal/length code";
5094 UNGRAB
5095 UPDATE
5096 return Z_DATA_ERROR;
5097 }
5098 } while (1);
5099 } while (m >= 258 && n >= 10);
5100
5101 /* not enough input or output--restore pointers and return */
5102 UNGRAB
5103 UPDATE
5104 return Z_OK;
5105 }
5106 /* --- inffast.c */
5107
5108 /* +++ zutil.c */
5109 /* zutil.c -- target dependent utility functions for the compression library
5110 * Copyright (C) 1995-1996 Jean-loup Gailly.
5111 * For conditions of distribution and use, see copyright notice in zlib.h
5112 */
5113
5114 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5115
5116 /* #include "zutil.h" */
5117
5118 #ifndef NO_DUMMY_DECL
5119 struct internal_state {int dummy;}; /* for buggy compilers */
5120 #endif
5121
5122 #ifndef STDC
5123 extern void exit OF((int));
5124 #endif
5125
5126 const char *z_errmsg[10] = {
5127 "need dictionary", /* Z_NEED_DICT 2 */
5128 "stream end", /* Z_STREAM_END 1 */
5129 "", /* Z_OK 0 */
5130 "file error", /* Z_ERRNO (-1) */
5131 "stream error", /* Z_STREAM_ERROR (-2) */
5132 "data error", /* Z_DATA_ERROR (-3) */
5133 "insufficient memory", /* Z_MEM_ERROR (-4) */
5134 "buffer error", /* Z_BUF_ERROR (-5) */
5135 "incompatible version",/* Z_VERSION_ERROR (-6) */
5136 ""};
5137
5138
5139 const char *zlibVersion()
5140 {
5141 return ZLIB_VERSION;
5142 }
5143
5144 #ifdef DEBUG_ZLIB
5145 void z_error (m)
5146 char *m;
5147 {
5148 fprintf(stderr, "%s\n", m);
5149 exit(1);
5150 }
5151 #endif
5152
5153 #ifndef HAVE_MEMCPY
5154
5155 void zmemcpy(dest, source, len)
5156 Bytef* dest;
5157 Bytef* source;
5158 uInt len;
5159 {
5160 if (len == 0) return;
5161 do {
5162 *dest++ = *source++; /* ??? to be unrolled */
5163 } while (--len != 0);
5164 }
5165
5166 int zmemcmp(s1, s2, len)
5167 Bytef* s1;
5168 Bytef* s2;
5169 uInt len;
5170 {
5171 uInt j;
5172
5173 for (j = 0; j < len; j++) {
5174 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5175 }
5176 return 0;
5177 }
5178
5179 void zmemzero(dest, len)
5180 Bytef* dest;
5181 uInt len;
5182 {
5183 if (len == 0) return;
5184 do {
5185 *dest++ = 0; /* ??? to be unrolled */
5186 } while (--len != 0);
5187 }
5188 #endif
5189
5190 #ifdef __TURBOC__
5191 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5192 /* Small and medium model in Turbo C are for now limited to near allocation
5193 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5194 */
5195 # define MY_ZCALLOC
5196
5197 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5198 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5199 * must fix the pointer. Warning: the pointer must be put back to its
5200 * original form in order to free it, use zcfree().
5201 */
5202
5203 #define MAX_PTR 10
5204 /* 10*64K = 640K */
5205
5206 local int next_ptr = 0;
5207
5208 typedef struct ptr_table_s {
5209 voidpf org_ptr;
5210 voidpf new_ptr;
5211 } ptr_table;
5212
5213 local ptr_table table[MAX_PTR];
5214 /* This table is used to remember the original form of pointers
5215 * to large buffers (64K). Such pointers are normalized with a zero offset.
5216 * Since MSDOS is not a preemptive multitasking OS, this table is not
5217 * protected from concurrent access. This hack doesn't work anyway on
5218 * a protected system like OS/2. Use Microsoft C instead.
5219 */
5220
5221 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5222 {
5223 voidpf buf = opaque; /* just to make some compilers happy */
5224 ulg bsize = (ulg)items*size;
5225
5226 /* If we allocate less than 65520 bytes, we assume that farmalloc
5227 * will return a usable pointer which doesn't have to be normalized.
5228 */
5229 if (bsize < 65520L) {
5230 buf = farmalloc(bsize);
5231 if (*(ush*)&buf != 0) return buf;
5232 } else {
5233 buf = farmalloc(bsize + 16L);
5234 }
5235 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5236 table[next_ptr].org_ptr = buf;
5237
5238 /* Normalize the pointer to seg:0 */
5239 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5240 *(ush*)&buf = 0;
5241 table[next_ptr++].new_ptr = buf;
5242 return buf;
5243 }
5244
5245 void zcfree (voidpf opaque, voidpf ptr)
5246 {
5247 int n;
5248 if (*(ush*)&ptr != 0) { /* object < 64K */
5249 farfree(ptr);
5250 return;
5251 }
5252 /* Find the original pointer */
5253 for (n = 0; n < next_ptr; n++) {
5254 if (ptr != table[n].new_ptr) continue;
5255
5256 farfree(table[n].org_ptr);
5257 while (++n < next_ptr) {
5258 table[n-1] = table[n];
5259 }
5260 next_ptr--;
5261 return;
5262 }
5263 ptr = opaque; /* just to make some compilers happy */
5264 Assert(0, "zcfree: ptr not found");
5265 }
5266 #endif
5267 #endif /* __TURBOC__ */
5268
5269
5270 #if defined(M_I86) && !defined(__32BIT__)
5271 /* Microsoft C in 16-bit mode */
5272
5273 # define MY_ZCALLOC
5274
5275 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5276 # define _halloc halloc
5277 # define _hfree hfree
5278 #endif
5279
5280 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5281 {
5282 if (opaque) opaque = 0; /* to make compiler happy */
5283 return _halloc((long)items, size);
5284 }
5285
5286 void zcfree (voidpf opaque, voidpf ptr)
5287 {
5288 if (opaque) opaque = 0; /* to make compiler happy */
5289 _hfree(ptr);
5290 }
5291
5292 #endif /* MSC */
5293
5294
5295 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5296
5297 #ifndef STDC
5298 extern voidp calloc OF((uInt items, uInt size));
5299 extern void free OF((voidpf ptr));
5300 #endif
5301
5302 voidpf zcalloc (opaque, items, size)
5303 voidpf opaque;
5304 unsigned items;
5305 unsigned size;
5306 {
5307 if (opaque) items += size - size; /* make compiler happy */
5308 return (voidpf)calloc(items, size);
5309 }
5310
5311 void zcfree (opaque, ptr)
5312 voidpf opaque;
5313 voidpf ptr;
5314 {
5315 free(ptr);
5316 if (opaque) return; /* make compiler happy */
5317 }
5318
5319 #endif /* MY_ZCALLOC */
5320 /* --- zutil.c */
5321
5322 /* +++ adler32.c */
5323 /* adler32.c -- compute the Adler-32 checksum of a data stream
5324 * Copyright (C) 1995-1996 Mark Adler
5325 * For conditions of distribution and use, see copyright notice in zlib.h
5326 */
5327
5328 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5329
5330 /* #include "zlib.h" */
5331
5332 #define BASE 65521L /* largest prime smaller than 65536 */
5333 #define NMAX 5552
5334 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5335
5336 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5337 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5338 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5339 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5340 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5341
5342 /* ========================================================================= */
5343 uLong adler32(adler, buf, len)
5344 uLong adler;
5345 const Bytef *buf;
5346 uInt len;
5347 {
5348 unsigned long s1 = adler & 0xffff;
5349 unsigned long s2 = (adler >> 16) & 0xffff;
5350 int k;
5351
5352 if (buf == Z_NULL) return 1L;
5353
5354 while (len > 0) {
5355 k = len < NMAX ? len : NMAX;
5356 len -= k;
5357 while (k >= 16) {
5358 DO16(buf);
5359 buf += 16;
5360 k -= 16;
5361 }
5362 if (k != 0) do {
5363 s1 += *buf++;
5364 s2 += s1;
5365 } while (--k);
5366 s1 %= BASE;
5367 s2 %= BASE;
5368 }
5369 return (s2 << 16) | s1;
5370 }
5371 /* --- adler32.c */
5372